Landscape Specification Guidelines - c.ymcdn.com Specication uidelines 3 xterior Landscape...

6th edition

Landscape Specification Guidelines

Exterior Landscape Installation

Landscape Specification Guidelines 2 Exterior Landscape Installation

1.0 General Conditions1.1 Scope of Work

A. The landscape contractor shall provide all materials, labor, and equipment to complete all landscape work as shown on the plans and specifications.

B. Total number of plants shall be drawn on the landscape plan. The landscape contractor shall state the total number of each plant with the contract price. The plant list submitted with the bid will automatically become part of the contract documents.

NOTE: If the contractor bids according to the Plant List, he/she should thoroughly check the plant list quantities with the symbols drawn on the plan to be sure there are no discrepancies. It is the landscape architect’s responsibility to be sure the plant count is correct on both the plan and the plant list, if used. Each plant grouping shall be labeled with the total number of plants per grouping by the landscape architect. If quantities are specified on a plant list, that list shall be accurate. If there is a discrepancy between the drawing and the list on the plans, the contract between the owner and the contractor shall take precedence.

C. The owner shall furnish a certified land survey of the site.

1.2 Standards

A. All plant material will conform to the current issue of the American Standard for Nursery Stock published by the American Nursery & Landscape Association (ANLA).Plant material must be selected from nurseries that have been inspected and certified by state plant inspectors.

B. Collected material may be used only when approved by owner’s representative.

C. Nomenclature will be in accordance with Hortus III, by L.H. Bailey.

1.3 Submittals

When requested by the owner or owner’s representative, samples of all materials other than plants shall be submitted to the owner’s designated representative for approval.

1.4 Approvals

All approvals shall be in writing.

1.5 Substitutions: Pre-bid

It is the landscape contractor’s responsibility to make every reasonable effort to find the material specified by the architect. The landscape contractor is responsible for qualifying his/her proposal to document any plant suitability or availability problems. The landscape contractor may offer substitutions to the landscape architect for his/her consideration. The landscape contractor will notify the landscape architect if there are known diseases or insect-resistant species that can be substituted for a selected pest-prone plant. The contractor shall submit a base bid as per plan, plus price clarifications for all recommended substitutions.

1.6 Substitutions: Post-bid

The intent is to eliminate post-bid substitutions. However, in the event that the contract material has become unavailable, an appropriate substitution must be approved by the owner’s representative.

1.7 Utilities and Underground Features

A. The landscape contractor shall notify utility companies and/or the general contractor in advance of construction to locate utilities (Miss Utility: www.missutility.net for MD, DC, and DE or http://va811.com for VA)

B. Street lighting and other private utilities, including cable TV, communication lines, etc., shall be located by the owner or general contractor.

C. If there is a conflict with the utilities and the planting, the landscape architect shall be responsible for relocating plants prior to the planting process. Any costs due to relocating after planting shall be borne by the owner.

D. Underground features, including, but not limited to, existing irrigation, septic systems, drain systems, invisible pet fencing, landscape lighting, underground natural gas, and security systems shall be located by the owner or general contractor.

1.8 Concealed Contingencies

The correction of undisclosed subsurface conditions, including, but not limited to, rock, roots, stumps, water, clay pan, soils contaminated with toxic substances, or other obstacles encountered in excavation work, that are not apparent at the time of estimating will result in additional costs to the owner. Upon discovery of undisclosed conditions, the landscape contractor shall notify the owner, with written approval regarding any additional costs, before corrective measures are taken.


1.9 Drainage

If plants are to be installed in areas that show obvious poor drainage, and the plants are inappropriate for that condition, the landscape contractor shall notify the landscape architect and owner. If deemed necessary, the plants shall be relocated, the contract shall be adjusted to allow for drainage correction at a negotiated cost, or the plant selection shall be modified by the landscape architect to accommodate the poor drainage situation.

1.10 Workmanship

A. During delivery and installation, the landscape contractor shall perform in a professional manner, coordinating his/her activities so as not to interfere unduly with the work of other trades, and leaving his/her work area(s) clean of litter and debris at the close of each workday.

B. During planting, all areas shall be kept neat and clean, and precautions shall be taken to avoid damage to existing plants, large trees, turf, and structures. Where existing trees are to be preserved, additional precautions should be taken to avoid unnecessary accumulation of excavated materials, soil compaction, or root damage. See the specification on Tree Preservation.

C. Upon completion, all debris and waste material resulting from planting operations shall be removed from the project and the area cleaned up.

D. Any damaged areas caused by the landscape contractor shall be restored to their original condition.

1.11 Water Supply

The owner shall supply water on site at no cost. If the landscape contractor has to supply water to the site, it shall be at an additional cost.

1.12 Planting Seasons

A professional horticulturist, nursery professional, or arborist shall be consulted to determine the proper time, based on plant species, climate, and weather conditions, (e.g. frozen ground, oversaturation) to move and install particular plant material to minimize stress to the plant. It is safe to plant year-round if certain criteria are followed. Plant material moved out of the normal planting season may require special treatment and will result in additional expense to the owner. The following guidelines should aid the landscape contractor and landscape architect in determining what and when to plant:

A. Stress Chart for B&B Deciduous Material

Lowest Risk

Highest Risk

1. Deciduous plants dug and planted while dormant in spring or fall except for those listed in G. below.

2. Deciduous plants dug during dormancy and planted after producing leaves, provided they have been properly stored.

3. Deciduous plants dug after leaves have fully expanded and hardened off.

4. Deciduous plants dug in the spring during newly expanding leaf production.

All woody plant material dug in full foliage between the months of May and September shall be handled in one of the following ways to harden-off:

1. Properly harden-off in the field 7–10 days prior to digging by a gradual process of trenching and soaking, leaving the bottom surface of the ball attached to soil until shipping.

2. Condition under irrigation in partial shade or sun for at least four days prior to shipping.

C. Container-grown and B&B deciduous material can be planted year-round, provided it receives adequate irrigation for the first growing season.

D. Herbaceous perennials and summer flowering bulbs can be installed as soon as the ground is workable in spring until November 15. Plants installed after November 15 require protective, supplemental mulch applied after December 15 and removed March 1.

E. Cold-sensitive annuals can be installed after danger of frost has passed.

F. Spring-flowering bulbs can be installed between September 15 and December 31.

G. Field-grown, balled and burlapped Red, White, Willow, and Scarlet Oaks; Dogwood; Sweet Gum; Leyland Cypress; and White Pine, and all broadleaf evergreens should be planted between March 1 and October 30 based on normal climatic conditions.

1.13 Inspection and Acceptance

A. Inspection: There should be a verification of performance for work by contract documents, to be conducted by the architect or owner’s representative on site and in the presence of the landscape contractor, for the purpose of acceptance. Inspection shall be made within two (2) weeks of


written notification from the landscape contractor. Failure of the owner to inspect the work shall void the guarantee. During inspection for initial acceptance, the landscape contractor should have an acceptance form to be signed by the owner or owner’s representative.

B. Initial acceptance: There should be an approval of the work inspected. Acceptance can be on partially completed work under the contract, if approved by the landscape architect or owner. If, for reasons beyond the landscape contractor’s control, work has stopped, inspection shall be made on partially completed work. Warranty shall begin after landscape inspection and acceptance. Maintenance after initial inspection and acceptance shall be the responsibility of the owner, unless an optional maintenance contract has been specified.

The landscape contractor should periodically inspect the site during the warranty period and notify the owner in writing if proper maintenance is not being performed.

C. Final inspection and acceptance: The landscape contractor shall conduct a final inspection with the owner or owner’s representative at the end of the one-year period.

1.14 Warranty

A. The standard warranty is for a one-year period, excluding bulbs, sod, and annuals, commencing on the date of initial acceptance. All plants shall be alive and in satisfactory health at the end of the guarantee period.

B. Any material that is 25% dead or more shall be considered dead and must be replaced at no charge. A tree shall be considered dead when the main leader has died back, or 25% of the crown is dead.

C. Perennials shall be guaranteed for one year after initial acceptance.

D. Warranty may be void if proper care, by owner or owner’s maintenance contractor, is not maintained.

E. Replacements shall be made during the next planting period.

F. The landscape contractor shall be responsible for a one-time replacement only.

G. Replacements shall be of the same type, size, and quality as original species unless otherwise negotiated.

H. The landscape contractor will not be responsible for

plant material that has been damaged by vandalism, fire, removal, relocation, wildlife, theft, or other activities beyond the landscape contractor’s control. Plant losses due to abnormal weather conditions, such as floods, excessive wind damage, drought, severe freezing, or abnormal rains will in no way be the responsibility of the landscape contractor.

I. Existing plant material transplanted shall not be guaranteed unless otherwise stated by the landscape contractor.

2.0 Plant Materials2.1 Scope of Work

The landscape contractor shall be responsible for furnishing and installing all plant material shown on the drawings and plant list, as submitted with the contract. The landscape contractor shall have investigated the sources of supply and satisfied himself/herself that he/she can supply all the plants specified on the drawings in the size, variety, quantity, and quality noted before submitting the bid. Failure to take this precaution will not relieve the successful bidder from the responsibility of furnishing and installing all the plant material in strict accordance with the contract requirements.

2.2 Standards

A. Plants will be in accordance with the current ANLA’s standards and conform in general to representative species.

B. Bare root

1. Bare-rooted shrubs shall be dug with adequate roots and root spread

2. Roots shall be protected during handling and planting to guard against drying out and damage.

C. Balled and burlapped (B&B)

1. Balled and burlapped plants shall be dug with firm root balls free of noxious weeds. There should be no excess soil on top of the root ball or around the trunk.

2. Ball sizes shall be in accordance with ANLA standards.

3. Caliper and height measurement: In size grading B&B single-trunk trees, caliper shall take precedence over height. Caliper of the trunk shall be taken 6" above ground level (up to and including 4" caliper size) and 12" above ground level for larger trees. For multiple-trunk trees, height measurement shall take precedence over caliper.


D. Container-grown stock

1. The size of container-grown shrubs is measured by height and width of plant. Herbaceous perennials shall be measured by pot size, not top growth. The root system of container-grown plants shall be well developed and well distributed throughout the container.

2. All container-grown trees and shrubs that have circling and matted roots shall be treated in the following manner prior to planting: using a knife or sharp blade, make 4-5 cuts, 1" deep, the length of the root ball, to cut all circling roots. See 6.3 Planting Procedures For All Container-Grown Trees & Shrubs in this section.

3. All container-grown plants should be grouped and watered adequately until they are planted in the landscape. To properly acclimate to new conditions after being planted in soil, soil must remain moist. Water twice weekly or at four-day intervals until the equivalent of one inch of rainfall or supplemental irrigation is received.

E. Root control bags—trees and shrubs: Plants grown in root control bags may be slightly larger than root ball sizes identified by ANLA standards. Before transplanting these into the landscape, the geotextile bag must be completely removed from around the root ball and the tree properly staked. See Section 5.2, Typical Upright Staking Detail. Adequate irrigation is essential to root control bagged trees and shrubs.

F. Trees shall be nursery-grown unless otherwise specified. Pruning shall be done before planting or during the planting operation. See section 4.4, Pruning Detail For Trees.

G. All plant material in transit shall be covered to keep material from drying out. The covering shall comply with state and local laws pertaining to the transport of materials.

2.3 Inspection

A. Plants may be subject to inspection and approval by the owner or owner’s representative at the place of growth or holding yard for conformity to specification requirements as to quality, size, and variety. It is the landscape contractor’s responsibility to know his/her sources. The landscape contractor shall select plants ahead of inspection visits to prevent rejection of materials delivered to the site. Cost of inspection visits shall be borne by each individual party.

B. Plants damaged in handling or transportation can be rejected by the owner or owner’s representative.

C. Plants with soil excessively covering the root flare, if not removed, can be rejected by the owner or owner’s representative.

D. Any plant material inspected at the place of growth, accepted, and tagged by the owner’s representative that has not been damaged during transportation cannot be rejected at the site as long as the tag remains attached to the plant.

E. State nursery inspection certificates shall be furnished to the landscape architect upon request.

3.0 Products3.1 Fertilizer

A. Perform a soil test to determine nutrient requirements. Apply fertilizer based on soil test results and recommendations.

B. Slow-release fertilizer should be the preferred type. The technical data sheet or label on the fertilizer should show that a minimum of 50% of the nitrogen source is water insoluble (WIN) and the salt index is less than 50. (Note: Salt index is relative to sodium nitrate, with a salt index of 100.)

3.2 Mulch

A. Organic material including shredded hardwood bark and ground wood waste shall be composted and mature. (Ref: Soils 2.1A)

B. Organic material shall be uniform in size and free of foreign matter.

C. Pine bark, pine needles, cypress bark, redwood bark, and cocoa shell do not need to be composted.

3.3 Stakes

Stakes shall be 2" x 2" hardwood or approved equal. See section 5.7 Tree Support Schedule for proper stake length.

3.4 Guying Material

A. Wire: 12 or 14 gauge galvanized steel or acceptable equal, depending on size of tree.

B. See section 5.7 Tree Support Schedule.C. Non-wire tie: Flat, woven, smooth, elastic tie

material (e.g., ArborTie®).

3.5 Turnbuckles

Turnbuckles shall be galvanized steel or zinc-coated. See section 5.7 Tree Support Schedule.


3.6 Hose

Hose shall be corded rubber, uniform in color and either 1/2" or 3/4" depending on the size of the tree. Other methods, such as straps or plastic chain locks, may be used where acceptable. See section 5.7 Tree Support Schedule.

3.7 Clamps

Clamps shall be galvanized, zinc- or vinyl-coated, and large enough to hold the wire or cable used.

3.8 Cable

Cable shall be galvanized steel. Level of strength and diameter depend on size of tree. See section 5.7 Tree Support Schedule.

3.9 Twine

Twine shall be 2–3-ply jute or an approved equal and biodegradable.

3.10 Prefabricated Tree Support Systems

Steel anchors. See section 5.7 Tree Support Schedule.

3.11 Tree Wrap

It is recommended that smooth bark trees be wrapped during dormant installation and removed when canopy is in leaf.

4.0 Planting Procedure for Trees4.1 Preparing Tree Pit

A. Walls of tree pit shall be dug so that they are vertical or sloping outward in heavy soils, and scarified.

B. The tree pit must be wide enough to adequately compact soil on every side of the tree’s rootball.

C. The tree pit shall be deep enough to allow 1/8 of the ball to be above the existing grade. Plants shall rest on undisturbed existing soil or well-compacted backfill.

D. Pits for bare-rooted trees shall only be broad enough to accommodate the roots fully extended and only deep enough so that the uppermost roots will be just below the original grade.

E. If poor drainage is suspected, a percolation test may be required. A 12-inch wide by 18-inch deep hole must be filled with water, and eight hours later, the hole should be empty. Sub drainage may be needed if the hole does not drain properly in eight hours.

4.2 Placing Tree in Pit

A. Identify the root flare and remove excess soil if necessary.

B. Place the tree in the pit carrying the ball and then lower it into the pit. Never lift the tree by the trunk or branches.

C. Set the tree straight and in the center of the pit with the most desirable side facing toward the prominent view.

D. For bare-rooted trees, set the tree in the pit so that all roots, when fully extended, will not touch the walls of the planting pit and the uppermost root is just below the original grade.

E. Remove containers from all container-grown trees. Slash the edges of the root balls from top to bottom, at least 1" deep, as described in section 6.3 Planting Procedures for All Container-Grown Trees and Shrubs. The slashing of roots may not be required for plants grown in a Cellugro system, in root containment bags, or in air-root-pruned containment systems.

4.3 Backfilling Tree Pit

A. Each site is unique. Soil tests should be used to identify special conditions. Backfill mixture for trees and shrubs shall be 3/4 existing soil mixed with 1/4 organic material, plus granular fertilizer. If compost is used, omit the granular fertilizer.

B. If any other additives are found to be needed at the time of planting, it shall be with the approval of the landscape contractor, landscape architect, and owner or owner’s representative at an additional negotiated cost.

C. Backfill tree pit with a soil mixture stated in the specifications, except where existing soil is suitable according to soil test results.

D. At the time of installation, you must cut and remove rope or wire back to the edge of the ball. Remove as much burlap, woven products, and twine as possible. All plastic or synthetic film or twine must be removed from the rootball. Cut all twine away from trunk. It is recommended that all materials be removed or pulled back 12" below the top of the rootball.

E. The tree must remain straight during backfilling procedure.

F. Thoroughly mix soil amendments, if needed, either prior to filling pit or as pit is being filled.


G. Backfill sides of tree pit halfway with soil mixture and tamp as pit is being filled. Do not over compact top 2/3 of planting mixture.

H. Finish backfilling sides of tree pit and tamp firmly.

I. Never cover top of rootball with soil.

J. Form a saucer above existing grade, around the outer rim of the tree pit, especially on slopes and in heavy soils.

K. Mulch top of root ball and saucer to a minimum depth of 2", not to exceed 3". Do not place mulch against the trunk.

L. Water thoroughly on the interior of the tree saucer until it is filled, even if it is raining. A second watering may be necessary to ensure saturation of the root ball and elimination of air pockets. An alternative watering method is to backfill half the pit, flood the pit, and completely backfill afterwards. Slow-release watering devices or automatic drip irrigation systems will improve survival.

M. Remove all tags, labels, strings, and wire from the tree, unless otherwise directed.

4.4 Pruning Details for Trees

A. Pruning should be restricted to corrective pruning only, including, but not limited to, dead/dying and/or crossing branches.

B. Do not cut main leader.

C. Make all cuts back to a lateral branch or bud. Cuts should be perpendicular above branch collar. See Exterior Landscape Maintenance specification.

D. Final pruning shall be done after tree is in place.

5.0 Bracing Procedures5.1 Tree Staking

A. The decision to stake should be made on an individual tree basis and should not be required for all plantings. It is recommended that all container and root control bag trees be staked.

B. Choose the correct sizes of stakes, hose, and wire according to section 5.7 Tree Support Schedule. Staking shall be completed as soon as possible after planting the tree.

C. Space stakes evenly and vertically on the outside of the tree ball and drive firmly into the ground. Never drive a stake through the rootball, as it will damage the tree’s root system.

D. Cut pieces of hose or nylon strapping material long enough to loop around the trunk of the tree.

E. Place the hose around the trunk at the height required to provide optimum support. Interlock hoses. Thread the wire through the hose and pull both ends horizontally 2' beyond the stake.

F. Twist the wire at the rubber hose to keep it in place. Wind both ends of the wire together around the stake twice and then twist wire back onto itself to secure. Cut off excess wire. The wire shall be 2–6" from the top of stake.

G. The above procedures are to be followed for each stake, keeping the tree straight at all times. For best establishment, there should be 1–3" sway in the tree.

H. It is the owner’s responsibility to remove stakes, wire, and hose one year after planting unless growing conditions warrant otherwise.

5.2 Typical Upright Staking Detail

5.3 Tree Guying

A. The decision to guy should be made on an individual tree basis and should not be required for all plantings.

B. Choose the correct sizes of stakes, hose, and wire according to section 5.7 Tree Support Schedule. Guying shall be completed as soon as possible after planting the tree.


C. Cut lengths of staking hose to extend 2" past tree trunk when wrapped around.

D. Space stakes evenly on outside of the tree saucer and drive each firmly into the ground. Stakes shall be driven at a 30º angle, with the point of the stake toward the tree.

E. Place the hose or nylon strapping material around the trunk, just above the lowest, stoutest branch. Interlock hoses.

F. Thread the wire through the hose and pull down the wire to extend 2' beyond the stake.

G. Twist the wire at the rubber hose to keep it in place. Wind both ends of the wire together around the stake twice and then twist wire back onto itself to secure. Cut off excess wire. The wire shall be 2" from the top of stake. If necessary, twist wires to tighten guy.

H. The above procedures are to be followed for each stake, keeping the tree straight at all times. For best establishment, there should be 1–3" sway in the tree.

I. Flag the guy wires with surveyor’s flagging tape or approved equal.

J. It is the owner’s responsibility to remove stakes, wire, and hose one year after planting unless growing conditions warrant otherwise.

5.4 Typical Tree Guying Detail

5.5 Guying With Prefabricated Cable Systems

A. The decision to guy trees should be made on an individual tree basis and should not be required for all plantings.

B. Choose the correct sizes and numbers of anchors, turnbuckles, and clamps and correct size of braided wire (cable) according to section 5.7 Tree Support Schedule. Anchoring shall be done as soon as possible after planting.

C. Drive anchors into ground to manufacturer’s recommended depth at final desired angle. Do not drive anchors straight into ground.

D. Set each anchor by inserting drive rod through cable loop attached to anchor by manufacturer, pulling cable upwards a distance slightly longer than the anchor body, thus rotating anchor approximately 90ºinto load lock position. Large anchors may require use of a come-along, jack, or post puller. Attach wire from anchor to the turnbuckle into a fixed position using clamps.

E. Loop wire from top of turnbuckle through 1/2" hose, around tree, and back through turnbuckle into a fixed position using clamps. Tighten turnbuckles to allow a 1–3" sway in the tree.

F. Flag the guy wires with surveyor’s flagging tape or approved equal. G. Owner should be notified in writing to remove wires and hose one year after planting unless growing conditions warrant otherwise.

G. It is the owner’s responsibility to remove cables and hose one year after planting unless growing conditions warrant otherwise.

5.6 Typical Tree Guying With Prefabricated Cable Systems


5.7 Tree Support Schedule

NOTE: General guidelines are as follows. Evergreens are more likely to require stakes or guying. Flowering/shade trees not exceeding 8' shall be staked at the landscape contractor’s discretion. The landscape contractor shall be responsible for maintaining trees in a straight, upright condition throughout the warranty period.

Tree Size

Height

Tree SizeCaliper (in)

Stake # Wire or Cable

Turn-buckle

Hose

6–8' 1–1½" 5' upright

2 14-gauge wire

- 1/2"

8–10' 1½"–2" 5' or 6'upright

2 14-gauge wire

- 1/2"

10–12' 2–2½" 7–8'upright

2 14-gauge wire

- 1/2"

12–14' 2½–3" 2' guy 3 12-gauge wire

- 1/2"

14–16' 3–4" 2' guy 3 12-gauge wire

- 3/4"

16–20' 4–6" 30" guy 3 12-gauge wire

- 3/4"

≥ 20' ≥ 6" Anchor 3 3/16" cable or as appropriate

3/8 x 6"

3/4"

6.0 Planting Procedures For Shrubs6.1 Planting Shrubs

A. For a single shrub, the pit shall be dug 1' wider than the diameter of the rootball and deep enough to allow 1/8 of the rootball to set above existing grade.

B. For a shrub mass planting, the entire bed area shall be tilled 4–6" deep, except within the critical root zone of existing plant material or where underground utilities are present. Tilling should only be done in moist soil to avoid compaction. If the soil is in clay or silt or loam, organic material should be added. Each shrub pit shall be excavated for the proper setting of the rootball. (Reference: Soils specification)

C. Place the shrub in the pit by lifting and carrying it by the rootball or container. Remove containers from all container-grown shrubs, slash the edges of the rootball from top to bottom, at least 1" deep. The slashing of roots may not be required for containers pre-treated with copper coating or plants grown in a Cellugro system or in root containment bags.

D. Set the shrub straight and in the center of the pit with the most desirable side facing toward the prominent view.

E. For individual shrub planting, use a backfill mixture as stated in section 4.3 Backfilling Tree Pit.

F. The shrub must remain straight during backfilling procedure.

G. Backfill sides of the pit halfway up with soil mixture and tamp as the pit is being filled.

H. Cut and remove rope or wire off the top of the rootball. Cut and remove as much burlap, woven products, and twine as possible. All plastic or synthetic film or twine must be removed from the rootball. Cut all twine away from trunk.

I. Finish backfilling the sides of the shrub pit and tamp firmly.

J. Form a saucer above the existing grade and completely around the planting pit.

K. Mulch top of rootball and saucer a maximum depth of 2". Keep excess mulch away from the trunk flare. To avoid insect/disease problems, mulch shall not come in to contact with woody plant material.

L. Water shrub or shrub mass thoroughly, even if it is raining. A second watering may be necessary to ensure saturation of the rootball and elimination of air pockets. An alternative watering method is to backfill half of the pit, flood the pit, and completely backfill afterwards. Slow-release watering devices or automatic drip irrigation systems will improve survival.

M. Prune out any dead or broken branches. Prune hedge as directed by landscape architect.

N. Remove all tags, labels, strings, wire, etc. from the plant, unless otherwise directed.

6.2 Planting Bare Root Material

A. The pit shall be only broad enough to accommodate the roots fully extended and only deep enough so that the uppermost roots will be just below the original grade.

B. Set the plant in the pit so that all roots, when fully extended, will not touch the walls of the planting pit, and the uppermost roots are just below the original grade.

C. Spread out the roots properly and work backfill mix among them. Prune off broken roots in a natural position. Water thoroughly while backfilling.

D. Complete the planting operation as detailed in section 6.1 Planting Shrubs.

6.3 Planting Procedures for All Container-Grown Trees and Shrubs

A. Remove the plant either by cutting or inverting the container.


B. For untreated plastic container-grown plants with circling roots, use a sharp knife to make four or five 1" cuts the length of the rootball.

C. Plant shrub or tree a minimum of 1/8 of the height of the rootball above existing grade.

D. Apply no more than a 2" thick layer of approved mulch. E. Plants grown in root containment bags must have the bags removed during the planting operation. No additional slashing of the rootball is necessary.

7.0 Planting Procedures for Ground Cover, Perennials, and Annuals

7.1 Preparing Ground Cover, Perennial, and Annual Beds

A. The planting bed shall be loosened by tilling when the soil is moist prior to planting. Soil shall be loosened to a depth of 4–6"except within the critical root zone of existing plant material or where underground utilities are present.

B. Organic matter shall be spread over the bed to a depth of 2" after the soil has been loosened. The organic matter shall then be worked into the bed by tilling. (Reference: Soils specification)

C. Fertilizer shall be top-dressed over annual bed area (except when compost is applied) based on soil test results. In the establishment stage, liquid fertilizer may be applied to annuals, as directed by owner or landscape architect.

D. The entire bed shall be mulched to a minimum depth of 1", 2" maximum, with approved mulch, such as pine fines, pine needles, or unscreened compost.

7.2 Planting Ground Cover, Perennials, and Annuals

A. Before planting, biodegradable pots shall be split, and non biodegradable pots shall be removed. Root systems of all potted plants shall be split or crumbled.

B. The plants, either potted or bare root, shall be installed so that the roots are surrounded by soil below the mulch. Potted plants shall be set so that the top of the pot is even with the existing grade. The roots of bare root plants shall be covered to the crown.

C. Spacing of plants shall be installed as noted on the landscape plan or contract.

D. The entire planting bed shall be thoroughly watered.

E. Treat the planted bed with a pre-emergent, soil-applied herbicide, per label instructions, unless otherwise directed by the owner or landscape architect. Apply the pre-emergent herbicide only when all foliage is dry to prevent foliar burn.

8.0 Planting Procedures for Bulbs8.1 Preparation of the Planting Bed

A. The planting bed shall be loosened prior to planting by tilling when the soil is moist, except within the critical root zone of existing plant material or where underground utilities are present. Depth of loosening depends on bulb species. See section 8.3 Bulb Planting Chart.

B. Organic matter shall be spread over the bed to a depth of 2" after the soil has been loosened. The organic matter shall then be worked into the bed by tilling.

C. Fertilizer shall be incorporated into the soil, except when compost is used, to the planting depth of perennials and bulbs. The fertilizer rate will be based on the results of the soil test. Annual bulbs do not require fertilizer.

D. The entire bed shall be mulched to a minimum depth of 1", 2" maximum, with approved mulch.

8.2 Planting Bulbs

A. Bulbs shall be installed by one of the following methods:

1. The bulb-planting hole shall be dug through the mulch with a hand trowel, bulb planter, or power auger.

2. Excavate to the recommended planting depth. Set out the bulbs and then cover the bulbs with soil.

3. Bulbs used as a single season display may be planted at a lesser depth.

B. Bulbs shall be planted so that the basal plate faces down in the planting hole.

C. Spacing of bulbs shall be installed as noted on the landscape plan or contract.

D. Treat the planted bed with a pre-emergent approved for bulbs, as per label instructions.


8.3 Planting Chart

See chart below.

8.4 Bulbs, Perennials, Tubers, Corns, Rhizomes

9.0 Mechanical Tree Planting9.1 General Conditions

A. Mechanical tree planters may be used for transplanting trees and other large plants whenever practical.

9.2 Selecting Size of Mechanical Digger

A. Determine the size of the plant to be moved.B. Use caliper inch as per ANLA standards to measure

all trees.C. The size of mechanical digger used will be based on

trunk diameter, species, time of year, and condition of tree and site factors.

D. Use the mechanical digger that will give a root equivalent to 9" or 10" of soil per inch of trunk diameter. Example: A 4" caliper tree should be dug with 36" or 40" tree spade to ensure proper root area during transplanting. For trees, this rule of thumb is generally used up to 10" caliper. Larger trees are generally dug with a backhoe, burlapped, and moved with a crane.

E. Balled and burlapped specifications: Ball sizes should always be of a diameter and depth sufficient to encompass enough of the fibrous and feeding root system as necessary for the full recovery of the plant. It is recognized that balling of nursery grown stock can be accomplished by hand digging or by using mechanical devices especially designed for nursery conditions. The use of digging machines is an acceptable nursery practice. See chart below for root ball sizes.

Ref: ANLA ANSI-Z60.1-2004

F. During the active growing season, a larger rootball is recommended to reduce transplanting shock.

9.3 Equipment

A. Mechanical diggers shall be in good condition to ensure a successful transplant.

B. All blades shall be aligned, free of damage, and sharpened on a regular basis.

C. The hydraulic system shall be leak-free to avoid damage to plants and property.

9.4 Procedure

A. It is recommended that field-grown stock be root-pruned 6 to 12 months before removal from the nursery.

B. Before digging the tree, skim off any weeds and excess topsoil from the ball. Avoid damaging any

Reprinted by permission from Landscape Designer & Estimator’s Guide. (Revised Edition) written by National Landscape Association


roots or trunk. Match the size of the rootball to the hole excavated for transplanting.

C. Digging

1. Prepare tree for digging:

a. Tie branches up or down to allow good access to the tree by the mechanical spade.

b. Prune only those branches interfering with the digging process.

c. Prepare and protect site as directed by the owner or landscape architect.

2. For digging trees on existing slopes, refer to section 9.7 Mechanical Tree Planting Detail for Sloped Areas.

3. Drop spades one at a time, alternating from one side to the other, to ensure even penetration and clean root cutting. Water injection is helpful at this point, if available on the machine. Presoaking the area 24 to 48 hours prior to digging is recommended.

4. After lifting the tree from the hole, using sharpened hand tools, cut any roots protruding from the spades.

5. If the tree is moved off site, it must be tarped to prevent water loss from leaves and stems.

6. Remove any loose debris and, if possible, tarp bottom of rootball before transporting.

D. Setting

1. Scarify sides of the hole to remove glazing. Plant tree into hole dug by tree spade at the same elevation as the tree’s original grade. Up to 1/8 of the rootball can be higher than the tree’s original grade but never deeper. Level and adjust tree to straighten it as blades are being removed.

2. Should voids exist between the hole and the rootball, fill with good grade of topsoil or clean existing soil.

3. Use a long, slender tool (e.g., shovel handle, digging bar) to pack excess soil tightly around the edge of the rootball and create a saucer around the tree as if hand planting.

4. Shave certain areas of the rootball, if necessary, in slope situations. Use extreme caution to minimize root disruption. Refer to section 9.7 Mechanical Tree Planting Detail for Sloped Areas.

5. Staking and mulching procedures shall follow those for B&B trees. See section 5.7 Tree

Support Schedule and section 9.5 Mechanical Tree Planting Detail on Level Grade.

6. Remove all string, tags, and seals, and prune any broken branches, unless otherwise directed.

7. Thoroughly water tree.

8. It is the owner’s responsibility to remove stakes, wire, and hose one year after planting, unless growing conditions warrant otherwise.

9.5 Mechanical Tree Planting Detail on Level Grade

9.6 Details on Transplanting Trees From Sloped Areas to Level Areas Using a Mechanical Tree Spade

Operator shall inspect the degree of slope where the tree is growing before digging the cavity.


9.7 Mechanical Tree Planting Detail for Sloped Areas

10.0 Planting Above Structure And In Raised Planters

10.1 Scope of Work

A. Furnish all labor, materials, tools, equipment, and services necessary to complete the following for on-structure planters as specified on drawings.

1. Installation of all drainage material.2. Installation of planter soil mix.3. Installation of plant materials.

B. The landscape contractor shall be familiar with the project premises and how the existing conditions will affect his/her work.

10.2 Related Work

• Soils (See Previous Section)• 1.0 General Conditions• 2.0 Plant Materials• 3.0 Products• 4.0 Planting Procedures For Trees• 5.0 Bracing Procedures• 6.0 Planting Procedures For Shrubs• 7.0 Planting Procedures For Ground Cover,

Perennials, And Annuals• 8.0 Planting Procedures For Bulbs

10.3 Testing

The landscape contractor shall test all planters for positive drainage after all waterproofing and protection board is installed, but prior to installation of drainage material.

10.4 Products

A. Filter fabric (i.e., soil separator) and drainage board are used in the bottom of the container to prevent soil from plugging drainage and/or weep holes.

B. Unless otherwise specified by the owner/owners representative, topsoil shall be sandy loam in texture, with a mechanical analysis of 50–60% sand, 15–25% silt, and 10–15% clay. The soil must be homogeneous throughout to ensure adequate drainage. C. Organic matter shall be composted pine bark, mature compost, or approved product. Organic material added to the topsoil must be uniformly mixed throughout the entire soil profile. D. The contractor should perform soil testing before the soil mix is installed into the planter to correct any nutrient deficiencies or perform any pH adjustment that may be necessary. The landscape architect should be on site to review all stages of planting in above structures and in raised planters.

10.5 Procedure

A. Drainage

1. Install drainage material in all planting areas over structure, as per plan. Areas to be planted must be clean of extraneous material and debris. Do not damage planter waterproofing or protection board. Ensure that planter drains are operable and free of debris. The landscape architect may review the installation of the drainage systems prior to placing any backfill mixes.

2. Install filter fabric or drainage board along planter bottoms. Make sure filter fabric or drainage board does not slip during the backfill installation.

B. Soil placement

1. Place soil in 12" layers and lightly tamp to eliminate air pockets and minimize settling. Care should be taken when placing soil so as to not compact and restrict drainage. Due to anticipated settling, soil fill may exceed final grade.

Prior to planting, the landscape contractor shall re-grade and repair any areas that settle or are uneven.

C. Planting operations: See sections 2.0 through 8.0 for planting materials and procedures.

D. Bracing operations: See section 5.4 for selection of bracing techniques. In some cases, galvanized steel eyebolts can be imbedded into the sides of the planter to allow the connection of guy wires.


11.0 Green RoofsRef: Maryland Department of the Environment – 2000 Maryland Stormwater Design Manual, Volume II Stormwater Design Appendices, Appendix B.4 Construction Specifications for Environmental Site Design Practices, Section B.4.A Green Roof Specifications

www.mde.maryland.gov/programs/water/stormwatermanagementprogram/soilerosi onandsedimentcontrol/documents/md%20swm%20volume%202.pdf

www.mde.maryland.gov/programs/water/stormwatermanagementprogram/soilerosi on andsedimentcontrol/documents/md swm volume 2.pdf

B.4.A Green Roof Specifications

1. Material SpecificationsBecause there is significant variation in green roof assemblies and methods, providing comprehensive specifications is not feasible. Material specifications for green roofs will vary based on each roofing system, and specific information should be obtained from the appropriate manufacturer or retailer. The following information and specifications, which include acceptable materials for generic applications, are not exclusive or limiting.

2. Planting MediaPlanting media should be a soil-like mixture with an organic content of 15% or less. The grain size distribution is necessary for attaining proper moisture content, permeability, nutrient management, non-capillary porosity, and soil structure. Grain size guidelines vary for single and dual media green roof assemblies.

The planting media shall be tested and meet the following criteria:

• Non-Capillary Pore Space at Field Capacity, 0.333 bar TMECC 03.01, A)

• Moisture Content at Field Capacity• (TMECC 03.01, A)• Maximum Media Water Retention (FLL)• Alkalinity, CaCO3 equivalents (MSA)• Total Organic Matter by Wet Combustion (MSA)• pH (RCSTP)• Soluble Salts (DTPA saturated media extraction–

RCSTP)• Cation Exchange Capacity (MSA)• Saturated Hydraulic Conductivity (FLL):

» Single Media Assemblies» Dual Media Assemblies» ≥ 15% (volume)» ≥ 12% (volume)

» ≥ 30% (volume)» ≤ 2.5%» ≤ 3–15% (dry wt.)» 6.5–8.0» ≤ 6 mmhos/cm» ≥ 10 meq/100 g» ≥ 0.05 in/min» ≥ 0.30 in/min

• Mineral Fraction Grain Size Distribution (ASTM D422):

» Single Media Dual Media» Clay Fraction (2 micron) 0 % Passing #200

Sieve ≤ 5% 5– 5%» % Passing # 60 Sieve ≤ 10% 10–25%» % Passing #18 Sieve 5–50% 20–50%» % Passing ⅛ inch Sieve 20–70% 55–90%» % Passing ⅜ inch Sieve 75–100% 90–100%» Appendix B.4. Construction Specifications

for Environmental Site Design Practices» Supp. 1 B.4.2

3. Green Roof LayersRoot barriers—should be thermoplastic membranes with minimum thickness of 30 mils.

Membranes certified for use as root barriers are recommended. However, only FLL currently offers a recognized certification test. Many FLL-certified materials are locally available.

• Granular drainage media—should be a non-carbonate mineral aggregate meeting the following specifications:

» Saturated Hydraulic Conductivity ≥ 25 inches/minute

» Total Organic Matter (by wet combustion) ≤ 1%» Abrasion Resistance (ASTM C131-96) ≤ 25% loss» Soundness (ASTM C88 or T103 or T103-91)

≤ 5% loss» Porosity (ASTM C29) ≥ 25%» Alkalinity, CaCO3 equivalents (MSA) ≤ 1%» Grain Size Distribution (ASTM C136)» Percent Passing #18 Sieve ≤1%» Percent Passing ¼ inch Sieve ≤ 30%» Percent Passing 3/8 inch Sieve ≤ 80%

• Separation fabric—should be a lightweight, non-woven geotextile that is easily penetrated by roots, while providing a durable separation between drainage and growth media layers.

• Separation fabrics should meet the following:• Unit Weight (ASTM D3776) ≤ 4.25 ounces per

square yard» Grab Tensile Strength (ASTM D4632) ≤ 90 lbs.» Mullen Burst Strength (ASTM D4632) ≥

135 lbs/inch» Permittivity (ASTM D4491) ≥ 2 sec-1

6th edition


Exterior Landscape Maintenance

Landscape Specification Guidelines 1 Exterior Landscape Maintenance


A. The landscape contractor shall provide all materials, labor, and equipment required to complete all landscape maintenance work as specified in the contract.


1.2 Standards

A. All landscape maintenance services shall be performed by trained personnel using current and acceptable horticultural practices.

B. All operators of power equipment shall conform to OSHA regulations.

C. All work shall be performed in a manner that maintains the original integrity of the landscape design.

D. All chemical applications shall be performed in accordance with current county, state, and federal laws, utilizing EPA registered materials and methods of application. These applications shall be performed under the supervision of a licensed certified pesticide applicator. For turfgrass fertilizer applications in Maryland, there is a Nutrient Management Certification required. All fertilizer applications made to turf must be made under the certified individual’s supervision. Selection of chemicals shall be in accordance with the following current University Extension Publications:

In Maryland:

Maryland Fertilizer Use Act of 2011 For Professional Fertilizer Applicators

Certification

Beginning October 1, 2013, anyone who applies fertilizer to turf as part of his or her job must be certified, or work under the direct supervision of someone who is certified.

General Requirements

Take soil test using an approved lab, initially and then every three years thereafter.

Follow the recommendations of UMD Extension: TT-115 for turf maintenance; TT-116 for seeding; or TT-118 for golf courses.

Keep records of fertilizer applications:DateLocationRate (e.g., 4 lb/1000 ft2)Total amount usedAnalysis of fertilizer

Do not apply fertilizer to impervious surfaces.

Nitrogen Limits

No more that 0.7 lb/1000 ft2 of soluble nitrogen may be applied in any one application.

No more than 0.9 lb/1000 ft2 total nitrogen may be applied in any single application, unless you are using an enhanced efficiency fertilizer.

Enhanced Efficiency Fertilizer

Defined as not having a release rate of more than 0.7 lb/1000 ft2 per month of nitrogen.

If using enhanced efficiency fertilizer, keep manufacturer’s documentation of release rate. May not be applied after November 15. May not apply more than 2.5 lbs/1000 ft2 of nitrogen using an enhanced efficiency fertilizer. May not apply more than 80% of annual recommended rate for nitrogen.

Phosphorus

Organic Turf Fertilizer:May not contain more than 5% P2O5.May not have an application rate greater than 0.25 lb/1000 ft2 of P205 per application or 0.5 pound/1000 ft2/year.

May not be used if soil test phosphorus level is optimum or excessive.

Timing Restrictions

No application of N or P2O5 to turf before March 1 or after November 15, except that between November 15 and December 1, ½ pound of soluble N may be applied. No application of N or P2O5 when the ground is frozen. Lime, K, and other nutrients are not regulated.

Setbacks

No application of N or P205 within 15 feet of water.

If using a drop spreader, rotary spreader with deflector shield, or targeted spray, the setback may be reduced to 10 feet.


Additional Information:Landscape IPM Guidelines for Integrated Pest Management, Bulletin 350.

• Total Crop Management of Herbaceous Perennials, Bulletin 359.

• Lawns and the Chesapeake Bay, Fact sheet 702.• Fertilizing Landscape Trees and Shrubs, Fact sheet

HG 23.• Fact sheets (printed and electronic) on specific

insects, mites, and disease control.• Fact sheets (printed and electronic) on turf disease

and weed control.• Other updated University of Maryland Extension

printed and electronically published literature: Nursery News, Green Industry News, Agronomy

Please visit www.mda.maryland.gov/fertilizer to download the Nutrient Management Manual for turfgrass fertilizer applications.

In Virginia:

Pest Management Guide, Horticulture and Forest Crops – Bulletin 456-017

Electronic pest management guides can be accessed at http://www.ext.VT.edu/pubs/pmg/

Fertilizer regulations can be accessed at www.dcr.virginia.gov/stormwater_management/nutmgt.shtml

In D.C.:

The District of Columbia does not have any fertilizer regulations.

All organic gardening shall not use synthetic chemical pesticides or synthetic fertilizers.

All companies using IPM shall have regular monitoring and tracking of pest populations as a central part of their program. Alternative methods to broad spectrum pesticide applications such as biological releases or selection of pest resistant plant material will be used where practical. Selective biorational and botanical insecticides will be used in controlling pest populations when possible.

1.3 Approvals

A. Any work performed in addition to that outlined in the contract shall only be done upon written approval by the owner or the owner’s representative.

B. All seasonal color selections, if not originally specified by the landscape architect, shall be approved by the owner or the owner’s representative prior to ordering and installation.

1.4 Soil Testing

Refer to the Soils specification, section 1.7 (Soil Testing).

1.5 Workmanship

A. During landscape maintenance operations, all areas shall be kept neat and clean. Precautions shall be taken to avoid damage to existing structures and plant material. All work shall be performed in a manner that ensures the safety of operators, occupants, and any pedestrians.

B. All fertilizers remaining on paved surfaces must be removed.

C. Upon completion of maintenance operations, all debris and waste material shall be cleaned up and removed from the site, unless provisions have been granted by the owner to utilize onsite trash receptacles or to compost on site.

D. Any damage to the landscape, the structure, the irrigation, and/or electrical systems caused by the landscape contractor shall be repaired by the landscape contractor without charge to the owner.

1.6 Warranty

The landscape contractor shall make every effort to maintain the health and growth of all plant material and turf. The landscape contractor shall not be responsible to guarantee the plant material or turf, except when that landscape contractor was obviously negligent in the performance of his/her work as outlined in the contract.

2.0 ProductsPesticides, fertilizers, lime, and other such products used in landscape maintenance operations shall be selected based on the most current information provided by the University of Maryland or Virginia Polytechnical Institute (VPI) and currently labeled by the EPA for its proposed use.

3.0 Turf3.1 Mowing and Cleanup

A. Prior to each mowing, all trash, sticks, and other unwanted debris shall be removed from lawns and all areas to be mowed.

B. Cool season grasses, including blue grass, tall fescue, perennial ryegrass, and others, shall be maintained at a height of 3½" to 4½" throughout the growing season.

C. It is not recommended to mow during extremely dry or wet conditions. During the mowing season, all


lawn areas shall be mowed every 7 to 10 days or as weather conditions dictate. This is best determined by blade growth, as only 1/3 of the blade should be removed at any one cutting. Caution shall be used to avoid any flying debris. Safety glasses and ear protection shall be worn during this operation.

D. The mowing operation includes trimming around all obstacles, removing excess grass clippings, and removing debris from walks, curbs, and parking areas.

CAUTION: String trimmers shall NOT come in contact with the bark of the tree.

E. When possible, on all maintained lawns, mulching mowers should be used.

3.2 Edging

Edging of all sidewalks, curbs and other paved areas should be performed once every other mowing. Debris from the edging operations shall be removed and the areas swept or blown clean. Caution shall be used to avoid any flying debris. Safety glasses and ear protection shall be worn during this operation.

3.3 Fertilization

Operating in Maryland

Nutrient management laws passed by the Maryland Legislature in 1998 require that University of Maryland nutrient management guidelines are followed on commercially managed turfgrass sites larger than 3 acres.

Fertilizer regulations can be accessed at www.mda.maryland.gov/fertilizer

Operating in Virginia

Fertilizer regulations can be accessed at www.dcr.virginia.gov/stormwater_management/nutmgt.shtml

Operating in District of Columbia

Presently, the District of Columbia does not have nutrient management laws, but it is still environmentally responsible to follow the guidelines used in Maryland or Virginia.

3.4 Lawn Weed Control

A. Chemical

1. Based on the previous year’s performance, a pre-emergent (soil-applied) herbicide may be applied, consistent with soil temperature requirements for the product being used and the state law, to help control the germination of crabgrass and other annual weed seeds.

2. A post-emergent (foliar-applied) herbicide shall be applied, if necessary, around mid-May to help prevent the growth of broadleaf weeds. A second application may be applied, if necessary, in late September to early October to help control fall weeds.

3. A non-selective pre- or post-emergent (soil- or foliar-applied) herbicide shall be applied, only when necessary, to walks, curbs, and other paved areas to help control the growth of weeds.

4. Selection and proper use of herbicides shall be the landscape contractor’s responsibility. All chemical applications shall be performed under the supervision of a licensed certified pesticide applicator. Read the label prior to applying any chemical.

B. Non-Chemical Alternatives to Herbicides1. Perennial weeds: The creeping-type of weedy

grasses such as Bermudagrass, Roughstalk Bluegrass, Nimblewill, and Quackgrass cannot be successfully removed by digging unless they exist in very small, isolated patches. Because bunchgrasses have few, if any, stolons or rhizomes, they can be controlled effectively by digging. Using a spade or shovel, cut around clumps of weed grasses. The cut should be outside of all plant parts and at least 2" deep. When digging small patches of creeping-type grasses, the outside edge should be 6–12" outside plant parts and at least 6" deep.

3.5 Insect and Disease Control

A. The contractor shall be responsible for monitoring the site conditions on each visit to determine if any insect pest or disease problems exist. The contractor shall identify the insect pest or disease, as well as the host plant, and then consult the most current edition of the University Extension Service’s “Pest Management Recommendations for Turf” for control. The certified pesticide applicator shall be familiar with the label provided for the selected product prior to application.

3.6 Irrigation

Refer to the specification on Irrigation, section 1.15 (Maintenance).

3.7 Renovation

All turf renovation shall be considered an extra to the contract. Renovations may include disking, tilling, aerating, and/or topdressing. If required, this work shall be performed in accordance with the most current industry standards. Information about lawn renovation can be accessed at www.ipmnet.umd.edu.


4.0 Trees, Shrubs, Herbaceous Perennials, and Ground Cover

4.1 Pruning

A. Please refer to the following for laws governing each jurisdiction:www.dnr.state.md.uswww.ddot.dc.govwww.dof.virginia.govwww.fairfaxcounty.gov

B. All ornamental trees, shrubs, and ground cover shall be pruned when appropriate to remove dead or damaged branches, maintain the natural form of the plant, and create the effect intended by the landscape architect or designer. Except for desired hedges, or to conform to design intent, all pruning and thinning of plants shall be done to retain their natural shapes. If previous maintenance practice has been to shear and ball, then a natural shape will be restored gradually. See diagram.

Plant Shapes

C. Pruning Guidelines

1. Prune those that flower before the end of June immediately after flowering. Flower buds develop during the previous growing season. Fall, winter, or spring pruning would reduce the spring flowering display.

2. Prune those that flower in summer or autumn in winter or spring before new growth begins, since these plants develop flowers on new growth.

3. Hollies and other evergreens may be pruned during winter so their branches can be used for seasonal decoration. However, severe pruning of evergreens should be done in early spring only.

4. Broadleaf evergreen shrubs would best be hand-pruned to maintain their natural appearance.

5. Hedges or shrubs that require shearing to maintain a formal appearance shall be pruned as required. Dead wood shall be removed from sheared plants before the first shearing of the season. See diagram below.

6. Conifers shall be pruned, if required, according to their genus.

a. Conifers should never be pruned to bare wood.

b. Yews, junipers, hemlocks, arborvitae, firs, spruces, and false-cypress may be pruned any time of the year. If severe pruning is necessary, it must be done in early spring.

c. Pines may be pruned within five weeks following total candle elongation by reducing the candle length. See diagram below.

7. Ground cover shall be edged and pruned as needed to contain them within their borders.

8. Thinning: Remove undesirable branches and water sprouts and suckers by cutting them back to their point of origin on parent stems. This method results in a more open plant, without stimulating excessive growth. Thinning is used on crape myrtle, lilacs, Viburnums, Smokebush, and others. See diagram below.


9. Renewal pruning: Remove oldest branches of shrub at ground, leaving the younger, more vigorous branches. Also remove weak stems. On overgrown plants, this method may best be done over a three-year period. Renewal pruning may be used on Abelia, forsythia, deutzia, Mockorange, Spiraea, and others. See diagram below. Some plants, like Smokebush, Vitex, Abelia, and Buddleia, may be cut down close to the ground in late winter and will regenerate.

D. Plants overhanging passageways and parking areas shall be pruned as needed.

E. Shade trees that cannot be adequately pruned from the ground shall not be included in the Maintenance Contract. This type of work shall be performed by a Maryland Tree Expert under a separate contract.

F. For more detailed information regarding the pruning of specific plants, refer to www.ipmnet.umd.edu.

4.2 Cleanup

Plant beds shall receive a general cleanup before fertilizing and mulching. Cleanup includes:

A. Removing debris and trash from beds.

B. Cutting back herbaceous perennials left standing through winter (e.g., ornamental grasses, Sedum Autumn Joy). Established beds may require dividing and thinning. See section on perennials.

C. Thoroughly weed area by manually removing all weeds, chemically treating all weeds, or a combination of the two.

D. Cultivate existing mulch and/or remove excess soil and/or mulch to expose the root flare and so that when new mulch is applied, there is no more than a total depth of 2" of mulch.

E. Edge previously mulched beds to create a 90-degree edge with a depth of 2" to 3", and remove resulting debris. Single tree plantings in turf shall have the trunk of the tree located in the center of the mulched area (tree ring).

F. If necessary or specified, a pre-emergent herbicide may be applied to the soil to inhibit the growth of future annual or biennial weeds. Organically maintained gardens shall not receive any pre-emergent herbicides.

4.3 Fertilizing

A. Fertilizer selection

Slow-release fertilizer should be the preferred type.

The technical data sheet or label on the fertilizer should show that a minimum of 50% of the nitrogen source is water insoluble (WIN) and the salt index is less than 50.

Slow-release fertilizers should be applied at a rate between 1 and 3 lbs of actual nitrogen per 1000 sq. ft. per application and shall not exceed 3 pounds of actual nitrogen per 1000 sq. ft. annually. Quick-release fertilizer should only be used when the objectives of fertilization cannot be met with slow-release fertilizer. Rates are between 1 and 3 lbs of actual nitrogen per 1000 sq. ft. per application and shall not exceed 3 lbs of actual nitrogen per 1000 sq. ft. annually. A soil test shall determine if phosphorus and potassium are required. In Maryland, a soil test is required to be done every three (3) years for turf and landscape beds. Follow the guidelines for other jurisdictions.

B. Fertilization area

The fertilization area shall be defined prior to application. Consideration shall be given to root accessibility, root location, fertilization objectives, and plant species. The area to be fertilized for shrubs shall be the area under the drip line of the plant. For trees, an area 1.5 times the drip line area can be fertilized. Inaccessible surfaces shall not be included in the rate of application. Overlapping fertilization areas shall be calculated once.

C. Fertilizer guidelines for fertilization of trees, shrubs, and ground covers

1. Trees. The fertilization of trees should be based on plant age, vigor, and maintenance program. Young trees that are producing 12" or more of new growth per year have an adequate supply of nutrients. This is especially true if the trees are growing in a well-fertilized lawn or garden area. The soil around young trees that are producing less than 12" of new growth per year should be tested and fertilized according to recommendations. Generally, the application of 2 to 3 lbs of a complete 50% organic fertilizer per inch caliper is recommended for both deciduous and evergreen species. The fertilizer is best applied by drilling 1" to 2" diameter holes drilled 8" to 10" deep at 2' to 3' intervals starting near the edge of the original root ball and extending 1/3 the distance beyond the drip line. One should avoid top-dressing shade trees by applying an excess amount of nitrogen on turf growing under the shade of trees.

The fertilization of mature trees should be limited


to maintaining vigor and color. If mature trees have good color and are producing a minimum of 8" to 10" of new growth, they have an apparent adequate supply of nutrients available. Many species of mature trees generally respond well to fertilizing or vertical mulching at 4- to 6-year intervals. The fertilization rate for mature shade trees is 3 to 4 lbs of a complete 50% organic fertilizer per inch diameter at breast height (DBH), starting at half the distance between the drip line and the trunk of the tree and extending 1/2 the distance beyond the drip line. The 1" to 2" diameter holes should be 8" to 10" deep and at 2' to 3' intervals. When vertical mulching, drill 3" diameter holes 10" to 12" deep at 2' intervals and fill the holes with screened compost.

2. Calculation of area for fertilizer application. Example:

A crabapple with a 20-ft branch spread will receive fertilizer. The area of a circle is calculated as πr2. Using 3.14 as the value of π and having a radius (r) of 10 ft., the area of this circle would be = 3.14 x 102 = 314 sq.ft.

If the tree is to receive 2 lbs of actual N/1000 sq. ft. then,2 lbs of actual N/1000 sq. ft. = x lbs of N1000 sq. ft.314 sq ft. x 1000 = 2 x 314x 1000 = 628

x 1000 = 628 1000 1000

x = .628 actual N/1000 sq ft. is applied to 314 sq. ft.

3. Application rate of fertilizer per tree status:

Status Rate/Year

Newly planted 0–1 lb N/1000 ft2/yearEstablished plants 2–4 lb N/1000 ft2/yearMature trees 1 lb N/1000 ft2/year

4. Fertilizer Application Methods

For surface application, all fertilizer shall be uniformly distributed within the defined area of fertilization. Surface application shall not be made where surface runoff is likely to occur. Where turf or ground cover exists, subsurface fertilization should be the preferred method of fertilization.

For subsurface dry fertilization holes, they shall be evenly spaced within the defined

fertilization area. Holes should be 1"–2" in diameter, spaced 12"–36" apart and 4"–8" deep. The fertilizer should be evenly distributed among the holes. The fertilizer should not be closer than 2" to the soil surface.

For subsurface liquid fertilizer injection, the injection sites shall be evenly distributed within the fertilization area. For liquid injection systems, the pressure should not exceed 200 lbs per square inch. Fertilizer should be evenly distributed between holes.

Foliar applications, injections, or fertilizer implants shall only be used when soil application of fertilizer is impractical or ineffective in achieving fertilization objectives.

5. Shrubs should only be fertilized when they lack good color and/or are not growing properly. Yearly fertilizing of shrubs results in excessive growth of many species, resulting in increase need for pruning to maintain size and shape. Fertilizer needs should be based on soil test results and cultural practices. Excessive use of mulch or repeated application of hardwood bark mulches can create nutrient deficiency symptoms by applying fertilizers. If the shrubs appear to have normal growth and color, they are best left alone.

6. Ground covers: Newly planted ground covers often benefit from being fertilized with a 50% organic complete fertilizer at the rate of 2 to 3 lbs. of fertilizer per 100 sq. ft. during the first two to three years following establishment, especially if the soil was not properly prepared. Once the ground covers are well-established, yearly applications of fertilizer can create conditions for invasion by disease-causing organisms. The need to apply fertilizers to established ground covers should be based on color, vigor, and soil test results.

4.4 Mulching

The use of mulch should be limited to a maximum total depth no greater than 2" and applied only where the existing mulch has been either cultivated into the soil or removed. Only composted hardwood bark mulch, pure pine bark mulch, composted mix pine bark mulch, or unscreened compost shall be used in beds containing shallow rooted woody species, herbaceous perennials, or annuals. The use of shredded wood, wood chips, and colored shredded wood waste should be limited to uses such as around well-established deep-rooted species, walkways, or play areas. Repeated applications


of double-shredded hardwood bark mulch should be minimized in order to avoid the accumulation of toxic manganese in soils.

If annual or biennial weeds are the primary reason for mulching, they are best controlled with the use of pre-emergent herbicides applied before the weed seeds germinate or with the use of post-emergent herbicide applied with a wick applicator or by spray applied to the foliage of the growing weeds. If there are perennial weeds that exist, physically remove or spot treat chemically with an herbicide before mulching or else they will grow through the pre-emergent barrier.

Special care shall be taken in the mulching operation not to over mulch or cover the base of trees and shrubs.

4.5 Weeding

A. All beds shall be weeded on a continual basis throughout the growing season to maintain a neat appearance at all times.

B. Pre and post-emergent (foliar applied) herbicides shall be used where and when applicable and in accordance with the product’s label.


The landscape contractor shall be responsible for monitoring the landscape site on a regular basis. The monitoring frequency shall be determined by joint consensus between the customer and contractor. Trained personnel shall monitor for plant damaging insect activity, plant pathogenic diseases, and potential cultural problems in the landscape. The pest or cultural problem will be identified under the supervision of the contractor. Monitor for weeds throughout the season, especially for invasive species. If any invasive species are found, take immediate action to remove.

For plant damaging insects and mites identified in the landscape, the contractor shall consult and follow the recommendations of the most current edition of the state University Extension publications on insect and disease control on landscape plant material. (Refer to section 1.2 of this specification.)

Plant pathogenic disease problems identified by the contractor that can be resolved by pruning or physical removal of damaged plant parts will be performed as part of the contract. For an additional charge, plant pathogenic diseases can be resolved through properly timed applications of fungicides when the customer authorizes. Fungicides are effective when applied before the symptoms are present on the plant and are applied on a preventative basis.

If the contractor notes an especially insect- or disease-prone plant species in the landscape, he or she will suggest replacement with a more pest-resistant cultivar or species that is consistent with the intent of the landscape design.

NOTE: For identifying plant-damaging insects and mites, a reference textbook that can be utilized is Insects That Feed on Trees & Shrubs, by Johnson & Lyon, Cornell University Press. For plant pathogenic diseases, three references are suggested: Scouting & Controlling Woody Ornamental Diseases in Landscapes and Nurseries, authored by Gary Moorman, published by Penn State College of Agriculture; Diseases of Trees and Shrubs by Sinclair, Lyon, and Johnson, published by Cornell University Press; and Total Plant Management for Herbaceous Perennials, a joint effort of the University of Maryland, Virginia Tech, and Cornell University and their specialists in various environmental fields. This publication is available at www.ipmnet.umd.edu.

4.7 Trash Removal

The landscape contractor shall remove trash from all shrub and ground cover beds with each visit. All trash shall be removed from turf areas prior to mowing.

4.8 Leaf Removal

Fallen leaves shall be mulched or removed from maintained areas on a contractual basis. If requested by the owner, supplemental leaf removals shall be performed by the landscape contractor at an additional cost to the owner.

4.9 Watering

A. If an irrigation system exists, the landscape contractor shall be responsible for monitoring its effectiveness and reporting any problems to the owner.

B. The landscape contractor shall not be responsible for any hand-watering of the trees, shrubs, or ground cover, except where feasible and at an additional cost to the owner.

C. In drought years, it is advisable for contractors to recommend watering to prevent damaging stress to landscape plants.

4.10 Espaliers

Espaliers may be formal or informal. Wires may be run horizontally across the structure, and branches may be attached to the wires or individually to masonry nails, screw eyes, or similar hardware. See diagram below.

A. Attach tie, covered wire, tape, or treated string to masonry nail, wire, or screw eye.


B. Tie open end around stem. Do not make tight. Leave room for stem to grow in diameter so it does not become girdled.

C. Prune so that branches protrude no more than 12–18" from side of structure. Selectively prune branches to maintain desired shape.

D. Check ties annually.

4.11 Vines

Vines usually have an indeterminate habit of growth. Most need to be restrained or restricted.

A. Prune vines away from windows, doorways, and other openings.

B. Restrict vigorous vines from clambering over other plants (e.g., wisteria, trumpet vine, Boston ivy, sweet autumn clematis). Some vines can be permitted access to other plants (e.g., clematis x ‘Jackmanii’).

C. Prune to maintain integrity of design. Do not permit vines to escape through the landscape. Understand the vine’s growth habit.

4.12 Miscellaneous

The following items shall be done one year after installation, if appropriate, at an additional cost to the owner.

A. It is the owner’s responsibility to remove stakes, wire, and hose one year after planting unless growing conditions warrant otherwise.

B. Remove excess soil from soil rings.

C. All dead or unhealthy plant material out of warranty shall be replaced upon the approval of plant selection and price by the owner.

5.0 Seasonal Color: Annuals and Bulbs

5.1 Seasonal Color Installation

The installation of perennials, annuals, and bulbs, unless specified herein, shall be performed by the landscape contractor at an additional cost to the owner.

Refer to the specification on Exterior Landscape Installation, sections 7.0 Planting Procedures for Ground Cover, Perennials, and Annuals and 8.0 Planting Procedures for Bulbs

5.2 Seasonal Color Maintenance

A. Perennialization of bulbs

1. After flowering, cut off spent flower heads.

2. Allow leaves of daffodils and hyacinths to remain for a minimum of six weeks after flowers have faded. Cut off at base.

3. Allow leaves of other bulbs to yellow naturally and then cut off at the base.

B. Flower Rotations

1. Bulbs: Remove the entire plant and bulb after flowers have faded, or at the direction of the owner. Install new bulbs if included in contract. See section 8.3 Planting Chart in the specification on Exterior Landscape Installation.

2. Annuals

a. Dead heading: Pinch and remove dead flowers on annuals as necessary.

b. Fertilizing: Perform a soil test every three years. If phosphorus is optimal then apply a slow-release fertilizer with a 1-0-1 analysis, such as a 20-0-20.

c. Removal: If fall plants are to be installed, summer annuals shall be removed in early fall when fall plants are available for installation. If not, summer annuals shall be left in the ground until the first killing frost and then removed, unless otherwise directed by the owner.

C. Perennials

1. Following the first growing season:

a. Fertilize perennials with a slow-release fertilizer or any 50% organic fertilizer; or mulch perennials with compost 1" deep.

b. Cut all deciduous perennials flush to the ground by March 1 (if this was not done the previous fall) to allow new growth to develop freely.

c. Mulch the perennial bed once in early spring at a 1/2"–1" depth. If soil is bare in late fall, re-mulch lightly after ground is frozen to protect perennials.


d. Inspect for insect or disease problems on perennials. Monitor and control slugs on Hostas and Ligularias. Powdery mildew on Phlox, Monardas and Asters can be prevented with properly timed fungicides or use of disease resistant varieties.

e. Weed perennial bed as specified in 4.5 Weeding in this section.

f. Prune branching species to increase density. Cut only the flowering stems after blooming. DO NOT REMOVE THE FOLIAGE.

2. The following fall cut back deteriorating plant parts unless instructed to retain for winter interest, e.g. Sedum ‘Autumn Joy’, ornamental grasses.

3. Long-term care:

a. Perennials will be divided when the center of the plant begins to die out or when plants display less vigor or flowering. Plants will be dug with a spading fork and divided by hand, nursery spade, or a sharp knife. Strongest divisions will be kept for replanting. Divisions will be large enough to make a good display for the following season.

Divide plants that overcrowd the space provided. Divide according to the species. Some need frequent dividing (e.g., Asters and Yarrow every two years), others rarely, if ever (e.g., Peonies, Hostas, Astilbe).

b. For detailed information regarding the care of specific perennials, refer to All About Perennials by Ortho; Perennials: How to Select, Grow & Enjoy by Pamela Harper and Frederick McGourty, H.P. Books Publisher; Herbaceous Perennial Plants by Allan Armitage, Varsity Press, Inc.; Total Plant Management of Herbaceous Perennials, www.ipmnet.umd.edu.

6th edition


Interior Landscape Installation & Maintenance

Landscape Specification Guidelines 1Landscape Specification Guidelines 1 Interior Landscape Installation & Maintenance

1.0 General Conditions1.1 Scope and Coordination

A. The landscape contractor shall recognize and perform in accordance with all stated intents, specifications, drawings, and stipulations contained or referenced herein.

B. The landscape contractor shall be familiar with the project premises and how the existing conditions will affect his/her work during both the installation and maintenance phases of this section.

C. Except as otherwise stated herein, the landscape contractor shall furnish all plants, materials, tools, equipment, and labor necessary to complete the work described herein. Further, it shall be the landscape contractor’s sole responsibility to make all arrangements for all required procurements, transportation, storage, and preparations.

D. All plants, materials, and other products to be supplied by the landscape contractor under this section shall be subject to inspection and approval by the landscape architect prior to their installation. Such inspection may be made at the landscape contractor’s facilities or at such other location(s) as may be designated herein.

E. All materials and hardware to be supplied by the landscape contractor that is not specifically described herein shall be of suitable construction/composition and quality to achieve their intended function within the interior landscape.

1.2 Foliage Plant Standards

A. The landscape contractor shall provide plants, as specified, of a quality and size equal to or surpassing Foliage No. 1 grade, as described in the Interior Plant Specifications section of The Guide to Specifications for Interior Landscaping, current edition, published by the Professional Landcare Network, hereinafter referred to as the PLANET Guide.

B. All plants provided under this section shall have been established in their present growing containers for at least six months prior to installation.

C. No plant(s) provided under this section that require staking in order to maintain an upright position shall be accepted.

D. All plants shall be acclimated at the nursery or at a designated storage area not less than two months prior to installation if originally grown under shade conditions. If grown under full sun, the

acclimatization period shall not be less than six months. During the acclimatization period, the light levels made available to the plant shall be gradually reduced to approximately 250-foot candles. The acclimatization process shall include consideration of temperatures, humidity, watering intervals, and fertilization schedule.

1.3 Guarantee and Maintenance Period

A. The landscape contractor shall maintain and guarantee all plants for a one-year period beginning on the date of installation. Maintenance shall consist of a regularly scheduled maintenance program carried out by trained service technicians.

B. A log or other written record of service shall be provided with each service visit. The service technician shall enter the date and maintenance tasks performed for each visit.

C. Service procedures shall be as follows:

1. Notify the owner of the service technician’s arrival and departure from the project premises.

2. Inspect soil moisture levels and replenish as necessary.

3. Trim and clean all foliage, remove debris, and add soil or topdressing, as required.

4. Maintain proper nutrient levels in the growing medium.

5. As possible, rotate plants to evenly expose all sides to an equal amount of light.

6. All measures, whether specifically referenced or not, that may be required to ensure the health and vitality of the plant material.

D. The implementation of control measures for pest and disease infestations shall be in strict compliance with all federal and local regulations. A Certified Licensed Pesticide Applicator shall be familiar with the label provided for the selected product prior to application.

E. The owner agrees that plants will not be moved without the landscape contractor’s consent and that the landscape contractor will not be responsible for damage to the plants caused by the owner.

F. Replacement:

1. The landscape contractor shall replace, throughout the guarantee period, any plants that die or, in the opinion of the landscape architect or owner’s representative, are in an unhealthy or unsightly condition. Replacements shall be


made promptly after direction from the landscape architect or owner’s representative. The cost of such replacements shall be borne by the landscape contractor at no additional cost to the owner. It is understood that routine replacements should occur automatically.

2. Plants that have deteriorated within the guarantee and maintenance period shall be replaced with a plant of the same size and variety unless the landscape contractor can show that this is reasonably impossible. In such a case, a substitute, as approved by the landscape architect or owner’s representative and that represents comparable value, will be allowed. There shall be no additional costs for replacement of any materials except for changes in size or value of the replaced item(s). Written approval of the change shall be secured from the owner’s representative and the landscape architect before the replacement is made.

1.4 Waiver of Landscape Contractor’s Plant Replacement Guarantee

A. In the event of any of the below listed situations, the owner shall release the landscape contractor from his plant replacement guarantee, as specified, and any resulting plant replacements shall be made at additional cost to the owner.

1. The occurrence of significant changes in plant location(s) without the landscape contractor’s prior knowledge.

2. The occurrence of vandalism or theft.

3. Extended heat or power failures of sufficient duration to damage plant health.

4. The absence of hot and cold running water at the project premises.

5. The occurrence of temperatures outside the range of 55ºF to 85ºF.

6. Lack of access to the project premises. Lack of access to all plants for maintenance purposes during regular service visit, unless negotiated otherwise.

7. Watering or other well-meaning care by any client’s or owner’s employees.

8. Accidental or malicious damage to plants or containers by employees, cleaning crews, or other personnel.

9. Lowering of lighting levels below those that were originally specified as a basis for plant

specification, or below those existing at the time of the initial quotation for the maintenance contract. A measured level of 65 foot-candles at desk height for 10 hours per day is considered an absolute lower limit for most plants.

10. Introduction of any liquids, such as cleaning chemicals, alcohol, or surgery fluids, into the plant’s soil, or the use of toxic gases, such as strong ammonia from floor cleaning and stripping.

2.0 Products2.1 Plants and Planting

A. Sterilized, soilless growing medium shall contain approximately 50% Canadian sphagnum peat, 35% composted pine bark, and 15% sand. Use of a premixed, proprietary planting medium specifically formulated for interior plants is acceptable, provided that it is approved by the landscape architect or owner’s representative. A list of ingredients and the percentage of each by volume shall be submitted and approved in writing by the landscape architect or owner’s representative.

B. Pine bark: shredded and well decomposed.

C. Peat moss: shredded sphagnum peat with a fiber length of 1/8" to 1/4" and a pH range of 3.1 to 5.0.

D. Inorganic soil additive: perlite (coarse texture), vermiculite, or approved equal.

E. Planting medium

1. Basic considerations: When selecting a soil media for interior plantings, various criteria should be considered:

a. Permanency of the planting

b. Moisture retention needed

c. Light level of the planting

d. System of irrigation to be used

e. Size of plant material being installed

f. Compatibility of rootball soil type to planting media

g. Physical support required to keep plants stable

2. Characteristics of Growing Media

a. Well drained, but not so coarse that water retention and distribution is inadequate

b. Relatively low in nutrients – avoid excess soluble salts

c. Free from soil pests such as fungus disease organisms, nematodes, insects, and weed seeds


d. Uniform from batch to batche. Favorable pH range (i.e., 6.0–6.5). All

planting media shall be amended with dolomitic limestone to adjust pH.

f. Free from after-sterilizing toxicity (i.e., low in ammonia, nitrates, salts, and other detrimental substances).

3. Options

a. Media with sterilized soil (e.g., 2-1-1 mix: 2 peat moss, 1 topsoil, and 1 perlite or vermiculite). Good with high light levels and large plant material.

b. Soilless media: a light, airy, well-draining media of neutral pH. Soilless mixes are used in many situations (e.g., with sub-irrigation systems, low-light level plantings, and smaller plant material). Soilless media is commercially available under many trade names. Most soilless mixes have a nutrient charge added to the mix along with a wetting agent. Ratio of bark-peat moss-inorganic additive shall be specified for the particular project.

c. Either soil mix shall have a final wetted pH of 6.0–6.5.

F. Gravel: Gravel for interior planters shall be 1/2" to 1" washed stone.

G. Drainage board: Shall be composed of expanded polystyrene (EPS) beads averaging 3/8" diameter, with not more than 10% being 1/8" diameter or less. The EPS beads are then bound together with a waterproof adhesive binder and molded into blocks, usually 4’ x 4’ x 2". It shall have 2.0 PCF-nominal density, and the coefficient of permeability shall be 1.24 cm/SEC (ASTM D-2434).

H. Filler board: Meant to be used above the drainage board layers as a filler where full depth of soil is not required. Filler board shall be EPS, a closed cell, resilient, lightweight, foamed plastic having a density between 1.0 and 3.0 PCF. The manufacturers of the filler board and drainage board shall participate in a certification program, as recommended by the Society of the Plastics Industry.

I. Subsurface drainage matting: two-layer composite, consisting of a polyester, non-woven filter fabric heat-bonded to a compression-resistant nylon matting of open, three-dimensional construction.

J. Filter fabric: nonwoven, heat-bonded geotextile fabric made of 100% polypropylene. The fabric is used to separate the soil from the drainage materials and shall extend up the sides of the planter walls at least 6".

K. Topdressing: shredded pinebark mulch, 1/2" maximum size, or as specified by the landscape architect or owner for specialized uses (e.g., pinebark nuggets, sheet moss, decorative gravel).

L. Plant material

1. Plant list: The landscape contractor shall be responsible for furnishing and installing all plant material shown on the drawings. The landscape contractor shall have investigated the sources of supply and satisfied himself/herself that he/she can supply all the plants specified on the plant list in the size, variety, and quality noted before submitting his/her bid. Failure to take this precaution will not relieve the successful bidder from the responsibility of furnishing and installing all the plant material in strict accordance with the contract requirements and without additional expense to the owner. Substitutions will not be permitted. If proof is submitted that any plant specified is not obtainable, a proposal will be considered for use of the nearest equivalent size or variety with an equitable adjustment of contract price. Such proof shall be substantiated and submitted in writing to the landscape architect or owner’s representative.

2. Canes, trunks, stems, and branches

a. Must be free of pests and pathogens which could, by their presence, induce or contribute to the decline of the plant.

b. Must be free of conspicuous scarring evidence; scars, conspicuous or not, must be substantially healed, providing no point of entry for deleterious harmful pathogens or boring insects. There must be no splitting of canes or trunks at branching points.

c. Dead wood and branches must be removed.

d. All canes or trunks must be well-formed.

e. Plant height: Overall plant height shall be measured from the base of the growing container to mean foliage top.

f. Cane heights: With some cane varieties, size is determined by the height of rooted canes. Cane heights shall always be measured from the base of the growing container. Overall height of the plant shall be from the base of growing container to the mean foliage top.

3. Foliagea. Must be free of pests and pathogens which

could, by their presence, induce or contribute to the decline of the plant.


b. Must be free of any chlorosis, yellowing, or poor chlorophyll formation; turgid and substantially erect; and substantially free of blemishes resulting from mechanical, chemical, pathological, or pest-induced damage.

c. Must be cleaned of all dust and waterborne pesticide and fertilizer residue at the time of project acceptance. Foliage shall be cleaned throughout the maintenance and guarantee period.

4. Root system and soil mass

a. The root system shall be well-developed and, upon inspection, shall be found to be free of pests and/or pathogens. Development shall be adequate to:

1. Be well distributed throughout the container, such that the roots visibly extend on all sides to the inside face of the growing container.

2. Conversely, the root formation within the container shall not have developed to the point where it becomes excessive (i.e., “pot bound”) and prohibits water from permeating to the fine water-absorbing root hairs.

b. The growing medium shall be composed of such constituents as may be necessary to provide:

1. Thorough drainage and satisfactory aeration of the root zone. This soil mass should be as uniform as possible.

2. Adequate moisture and nutrient retention as may be necessary to promote vigorous but controlled plant growth.

3.0 Execution3.1 Procurement and Inspection of Plants

A. In the event that the owner chooses to be involved in a trip(s) to the source of plant material for the purpose of locating, selecting, or approving plants, it will be at the expense of the owner. The landscape architect may accompany the landscape contractor to his previously determined sources and inspect plants and growing conditions. Specimen plants may be tagged by the landscape architect prior to any digging, root pruning, top pruning, or preparation for shipment.

B. Digging and handling major plant material: All material shall be inspected and approved by the landscape architect or owner’s representative.

C. Balled and burlapped (B&B) plants shall be dug with firm, natural balls of earth of sufficient diameter and depth to include the fibrous and feeding roots. No plants will be accepted if the ball is cracked or broken before or during planting operations.

3.2 Plants and Planting

A. The landscape contractor shall coordinate all delivery and installation activities and he/she shall inform the owner at least 48 hours prior to commencement of work at the project premises.

B. All transport of plants shall be via enclosed and environmentally controlled vehicles by personnel experienced in handling live plants.

C. Unless otherwise stated herein, it shall be the landscape contractor’s responsibility to protect plants from adverse environmental conditions during all phases of delivery and installation. Further, the landscape contractor shall be responsible, except as otherwise stated herein, to protect all plants stored at the project premises during installation from any and all damage or deterioration of health or appearance.

D. During delivery and installation, the landscape contractor shall perform in a professional manner, coordinating his/her activities so as not to interfere unduly with the work of other trades and leaving his/her work area(s) clean of litter and debris at the close of each workday.

E. The landscape contractor shall maintain a qualified planting foreman at the project premises.

F. Upon completion of the installation, the landscape contractor shall so notify the landscape architect or owner’s representative and schedule an inspection of the work.

G. The landscape contractor shall promptly correct any deficiencies found in the installation as a result of the inspection. Upon final approval by the landscape architect or owner’s representative, the installation phase of this agreement shall be declared complete.

3.3 Planting

A. For major installations, the landscape architect or owner’s representative shall be notified at least four (4) days in advance of the plants arriving on the job site. Having arrived, the plants shall be handled and protected so as to maintain their condition until planted. The poor condition of a plant or group of plants may cause rejection by the landscape architect or owner’s representative. All rejected material shall be removed promptly from the site.


B. Planting tree pits

1. Backfill tree pits with 8" of washed stone—1/2" to 1" diameter—or with drainage board.

2. Install 2" diameter black corrugated plastic pipe with black cap for inspection and siphoning.

3. Install soil separator on top of the stone or drainage board. Be sure to extend the soil separator up the sides of the planting pit 4" to lock in place.

4. Backfill with soil mix, as specified, to a depth that allows the top of the root ball to sit 4" below the top of the adjacent paving.

5. Install the tree in the pit. Remove burlap from top of rootball on B&B trees prior to backfilling. Backfill around the ball as appropriate.

6. Place 2" of shredded bark mulch over the top surface of the tree pit, bringing the finished grade of the bed to 2" below the top of the pavement.

C. Planting raised planters

1. Place drainage material to within 6" of the bottom of the rootball of the plant material.

2. Install 2" diameter black corrugated plastic pipe, vertically, with black cap for inspection and siphoning.

3. Install soil separator over the drainage material. Be sure to extend the soil separator up the planter walls 4" to lock in place.

4. Backfill and compact with approved planting medium.

5. Set plants flush with the top of the bed, at 2" below the top of the planter wall. Large trees, 10’ tall or greater, shall be planted 10% above the finished grade.

6. Install a 2" layer of pinebark, shredded hardwood mulch or material approved by landscape architect or owner’s representative.

D. Fixed planting beds: Generally such beds shall be directly planted, removing nursery pots from plants. Follow procedure outline in C. above for raised planters.

E. Movable decorative planters (i.e., floor planters, file-top, and hanging planters):

To achieve aesthetic and horticulturally sound plantings, the landscape contractor shall employ methods as indicated on the drawings. Both “double- potting” and “direct planting” are acceptable methods of planting. Plants are to be placed plumb and secure within planters.


F. Seasonal and other: For frequent rotational plantings (fixed or movable planter), when foliage or seasonal potted flowers are to be changed frequently, “triple- potting” can both facilitate the removals and installations and allow for an extreme variety of watering requirements.

6th edition


Irrigation

Landscape Specification Guidelines 1Landscape Specification Guidelines 1 Irrigation


A. The intent of this specification is to define contractor/owner responsibilities and specify minimum standards for materials and workmanship.

1. Any residential system over 24 zones shall be considered commercial for the purposes of these specifications.

B. Irrigation layout/design shall meet the following parameters:

1. Head to head spacing to ensure 100% coverage.

2. Matched precipitation rates within a zone.

3. Pipe sized to stay at or below 5 feet per second.

4. Separation of zones by different types of plant material (e.g., turf, trees and shrubs, annuals).

5. Rain sensor shall be included.

6. Commercial projects must be designed and stamped by a Certified Irrigation Designer as designated by the Irrigation Association.

C. Furnish all labor and materials, appliances, tools, equipment, facilities, transportation, and services necessary for and incidental to perform all operations in connection with the installation of the irrigation system.

D. All local, municipal, and state laws, rules, and regulations governing or relating to any portion of this work are hereby incorporated into and made a part of these specifications.

E. Work noted “N.I.C.,” “existing,” or “to be supplied and/or installed by others” is not part of this section.

F. Due to the scale of drawings, it is not possible to indicate all offsets, fittings, sleeves, and other materials that might be required. The drawings are generally diagrammatic and indicative of the work to be installed. The work shall be installed in such a manner as to avoid conflicts between irrigation system, planting and architectural features. Work called for on the drawings by notes or details shall be furnished and installed whether or not specifically called out in the written specifications.

G. If discrepancies exist between drawings and specifications, and no specific interpretation is issued prior to bidding, the decision regarding any interpretation will rest with the owner’s representative. The contractor is to act on this decision as directed. In the event that the installation deviates from the direction given, it shall be corrected at the contractor’s expense.

1.2 Standards

A. The contractor shall obtain and pay for all permits and inspections required by outside agencies.

B. All materials shall meet minimum industry standards.

C. The system shall be installed as per manufacturer’s recommendations by qualified, trained personnel.

1.3 Quality Assurance

A. Commercial Projects

1. The company engaged in the project must have three years of experience with projects of similar size and scope.

2. The company must employ at least one full-time individual who maintains a current Certified Irrigation Contractor designation by the Irrigation Association.

B. Residential Projects

1. The company engaged in the project must employ an individual with one year of irrigation installation experience.

1.4 Submittals

A. For commercial projects, prior to the start of installation, the contractor shall submit for approval to the owner or owner’s representative a materials list indicating the name of the manufacturer, model numbers, and performance data for the following:

1. Sprinkler heads

2. Valves and valve boxes

3. Controllers and appurtenances

4. Pumps

5. Backflow

6. Drip equipment

7. Wire and electrical connection waterproofing method and materials

8. Grounding equipment

9. Pipe and fittings

10. Water harvesting and storage components (pre-filters, post-filters, storage vessels and associated control systems)

B. At completion of the installation, the contractor shall submit a minimum of four (4) individually bound copies or a PDF file of the irrigation system Operation and Maintenance Instructions, including


a materials list, “As-Built” drawing, suggested operating schedule, seasonal shut-down procedures, and the name and phone number of the installing contractor.

1.5 Approvals

All approvals shall be in writing from the owner or owner’s representative prior to installation.

1.6 Substitutions

It is the contractor’s responsibility to make every reasonable effort to use the material specified by the designer. The contractor may offer substitutions to the owner’s representative for consideration.

1.7 Existing Utilities

A. Prior to excavation, utility companies shall be notified in accordance with local codes and ordinances.

B. The contractor shall immediately notify appropriate utility of any inadvertent damage caused by the contractor’s operation.

C. The contractor shall not be responsible for “private utilities” unless accurate as-built drawings are supplied prior to the commencement of work.


The contractor shall not be liable for additional excavation expenses resulting from undisclosed subsurface conditions, such as, but not limited to, rock, water, clay pan, soils contaminated with toxic substances, or other obstacles encountered in excavation work that are not apparent at the time of estimating.

1.9 Water Supply

A. The location and size of the water supply shall be as per the drawing and installed in accordance with all applicable codes and ordinances.

B. An irrigation isolation valve shall be installed as the first component of the system on the exterior of the building. This valve shall be a bronze or PVC ball valve.

C. All piping above ground shall be copper (see section 2.3).

D. Copper piping shall terminate and transition to PVC with a copper female adapter and a schedule 80 PVC nipple. Copper male threaded connections are not acceptable.

1.10 Primary Electrical Supply

A. Unless noted on the drawing, the primary electrical source shall be a 120V AC, single-phase circuit.

B. Electrical circuits required for additional devices shall be noted by the contractor in the drawings and contract documents.

1.11 Product Handling

A. Materials used in the system shall be new and unused.

B. Store materials at a location directed by the owner’s representative. Store materials in an orderly manner and avoid interference with other construction activities.

C. Protect all materials to prevent the intrusion of dirt and moisture.

1.12 Workmanship

A. During delivery and installation, the contractor shall perform in a workmanlike, professional manner, coordinating installation activities so as not to interfere unduly with the work of other trades on site.

B. During installation, all areas shall be kept neat and clean. Precautions shall be taken to avoid damage to existing plants, turf, and structures. The contractor shall notify the owner in writing of potential damage to all trees and other plant material that may be destroyed or damaged beyond repair during construction. Such notice shall relieve the contractor of responsibility for said damage. Failure to notify the owner of potential damage may make the contractor liable for tree and plant replacements. Replacements shall be included in the one-year warranty.

C. The contractor shall park all employee or company vehicles only in areas designated by the owner’s representative.


A. Inspection: There should be a verification of performance for work by contract documents, to be conducted by the architect or owner’s representative on site and in the presence of the irrigation contractor, for the purpose of acceptance. Inspection shall be made within two (2) weeks of written notification from the irrigation contractor. Failure of the owner to inspect the work shall void the guarantee. During inspection for initial acceptance, the irrigation contractor should have an acceptance form to be signed by the owner or owner’s representative.

B. Initial Acceptance: The approval of work inspected.


Acceptance can be on partially completed work under the contract, if approved by the landscape architect or owner’s representative. If, for reasons beyond the irrigation contractor’s control, work has stopped, inspection shall be made on partially completed work. The warranty period shall begin after inspection and acceptance. Maintenance after initial inspection and acceptance shall be the responsibility of the owner, unless an optional service contract has been specified.

1.14 Guarantee

A. The contractor shall guarantee all labor, workmanship, materials, fixtures, and equipment covered by the contract documents to be free of defects for a period of one (1) year from the date of substantial completion and acceptance of the project. The contractor shall replace any part(s) found to be defective within the period of the guarantee at no cost to the owner, except repairs or replacement necessitated by damage by others.

B. Backfilling of all excavation shall be guaranteed. If, at any time during the one year guarantee period, trenches should settle, the contractor shall repair any settling at no cost to the owner.

1.15 Maintenance

During the warranty period, the installing contractor must perform all maintenance of the system. Unless called out in the contract, maintenance of the system shall be addressed under a separate contract. Negligence on the owner’s part to properly maintain the system or service to the system by another contractor may be used as grounds to void all warrantees.

A. Fall maintenance shall include (but not be limited to) draining of the system by compressed air.

B. Spring maintenance shall include (but not be limited to) the closing of all manual drain valves, inspection and realignment of all heads, operational check/test each zone for proper operation, and inspection and adjustment of controller and run times. A written report of work completed and/or necessary repairs and recommended modifications shall be provided after each service.

C. Periodic maintenance may be scheduled throughout the season to verify the proper operation of the system and to maintain the warranty within the warranty period. Maintenance shall include inspection and realignment of all heads, operational check/test of each zone for proper operation, and inspection and adjustment of controller and run

times. A written report of work completed and/or necessary repairs and recommended modifications shall be provided after each service.

D. The frequency shall be as stipulated in the maintenance contract.

1.16 Record Drawings

A. The owner shall provide an electronic copy of the landscape plan in AutoCAD or PDF. In the absence of a landscape plan, a site plan shall be provided.

B. The contractor shall, during the progress of work, keep an accurate daily record of all changes and corrections to contract drawings.

C. “As –Built drawings” shall indicate point of connection; control valve wire routing paths; controller location; electric, isolation, drain, and quick coupling valves; piping; and sleeves. For two-wire systems, locations of switches, decoders, and surge arrestors shall be noted.

D. Accurately locate all dimensions from a minimum of two permanent reference points (buildings, monuments, sidewalks, curbs or pavements). Do not use these prints for any other purpose.

E. When record drawings have been approved by the owner’s representative, the contractor shall provide drawings as an electronic PDF. The quality and presentation of the completed reproducible shall be acceptable to the owner’s representative.

F. The irrigation legend must be changed to accurately reflect the irrigation equipment installed, if such equipment is not the same as originally specified.

2.0 Materials2.1 General Conditions

The materials chosen for incorporation in the irrigation system may have been recommended by a specific manufacturer to enable the owner to establish the level of quality and performance desired. Substitution of equipment of another manufacturer may be allowed only after submittal to and approval by, the owner or owner’s representative. Refer to section 1.7.

2.2 Copper Pipe and Fittings

A. Pipe: Minimum Type “L”

B. Fittings: Wrought or cast copper, solder, flared, or threaded joint type

C. Joints shall be soldered in accordance with current NSF (National Sanitation Foundation) requirements.


2.3 Brass Pipe and Fittings

A. Brass pipe shall be 85% red brass, American National Standard Institute (ANSI), schedule 40 threaded pipe.

B. Fittings shall be medium brass, threaded 125 pound class.

2.4 Plastic Pipe, Fittings, and Adhesives

A. PVC Pipe and Fittings: Manufactured from virgin polyvinyl chloride compound in accordance with ASTM D 2241 and ASTM D 1784.

1. Identify all pipe with the following indelible markings:

a. Name of manufacturer

b. Nominal pipe size

c. Schedule or class

d. Pressure ratings psi

e. NSF seal of approval

f. Date of extrusion

2. Minimum class or schedule

a. 1/2", schedule 40.

b. 3/4" +, Cl. 200-SDR 21.

3. Sizing

a. Maximum velocity in pipe shall be 5 feet per second.

4. Pipe type

a. 2" and smaller shall be bell ended, solvent weld.

b. 3" and larger shall be gasket joint.

5. Fittings:

a. 2" and smaller PVC pipe–standard weight, schedule 40, injection molded PVC. Comply with ASTM D 1784 and D 2466.

b. 3" PVC pipe–PVC or ductile iron gasketed fittings for all applications.

c. 4" and larger PVC pipe–ductile iron gasketed fittings at all changes of direction and ends of pipe lines. PVC plastic gasketed fitting for all other applications.

6. Threaded nipples: ASTM D 2464, schedule 80 with molded thread(s), TOE or TBE.

7. Connections

a. Solvent weld: Joint cement and primer as recommended by manufacturer of pipe and fittings.

b. Gasketed: Gasket material and lubricants as recommended by manufacturer of pipe and fittings.

c. Threaded connections: PVC male adapters shall be used in plastic-t to-plastic connections. PVC-to-metal connections shall be metal female adapters and schedule 80 PVC nipples.

8. HDPE

a. Pipe: DR 13.5

b. Fittings: butt fusion, socket fusion, or electro fusion

c. Mechanical fittings: Pack joint fitting = grip joint fitting with set screw

9. Polyethylene pipe and fittings: Manufactured from virgin polyethylene, in accordance with ASTM D 2239 and PE 2306

a. Fittings: Manufactured in accordance with ASTM D 2609, PVC type I

b. Clamps: Stainless steel screw or crimp clamps

2.5 Valves

A. Remote control valves shall be normally closed, 24-volt electric with plastic or bronze body. Valve shall be equipped with a bleeder valve to permit operation in the field.

B. Isolation valves

1. 2" and smaller, shall be domestic bronze gate valves with non-rising stem (bronze cross handles or bronze wheel handles used below grade) meeting MSS SP-80 or PVC ball valves constructed from Type I PVC, ASTM D1784 with EDPM O rings and full bore flow.

2. Isolation valves 2 “ and larger, unless noted on the drawings, shall be resilient wedge, epoxy coated, 250 psi rated working pressure, cast iron gate valves with non-rising stem and conforming to AWWA C509.

C. Quick-coupling valves

1. Valves shall be hinged cover, brass body, 150 lb class with female threads at the base. Valve design shall permit operation with a special connection device (key) designed for this purpose.

2. Swing joints shall match inlet size of quick coupler and be a triple ‘O’ ring, pre-fabricated triple swing joint, having an integral metal transition fitting and having the ability to be anchored for stability.


D. Unless otherwise noted, manual drain valve shall be a bronze or PVC ball valve.

E. Valve boxes shall be provided for all manual valves, electric valves, air relief valves, decoders, two-wire switch devices, drip flush valves, ground rods, and wire splices.

2.6 Sprinkler Heads

A. Sprinkler heads shall be as shown and/or as required to coincide with the needs of the landscaping. Do not exceed the maximum or minimum spacing indicated by manufacturer.

B. All heads within a zone operated by the same valve shall have matched precipitation rate.

C. Sprinkler bodies may be brass or plastic material. Connections to lateral lines shall be either flex-swing pipe over barbed fittings or 3-ell swing joints.

D. Nozzles may be brass or plastic material.

2.7 Water Conservation Devices

A. Rain sensors shall be devices adjustable to react to rainfall from 1/8" to 1" by temporarily shutting down the automatic operation of the system.

B. Moisture sensors shall be adjustable and compatible with the controller installed. The sensor, in conjunction with the controller, shall be capable of automatically stopping and restarting irrigation watering based upon a set moisture level.

2.8 Wire

A. Control wire shall be UL/UF direct burial, sized as indicated or as required by valve and controller manufacturer’s recommendations.

B. Wire splice connectors shall be waterproof, made for direct burial, UL listed and rated for at least 30 volts.

C. Wire and splices for two wire systems must be as specified by the manufacturer.

2.9 Controller

A. The controller shall be as indicated, UL-approved for indoor or outdoor installation as required, with low voltage output (i.e., <30 Vac).

B. The controller shall be fully automatic and have the following minimum features:

1. Capable of operating the number of remote control valves indicated on drawings

2. Three programs

3. Rain delay

4. Multiple schedules to include odd/even, calendar, interval

5. An integral sensor terminal and circuit

C. The controller shall be grounded as per manufacturer’s recommendations.

2.10 Sleeves

A. SDR 21, CL 200, bell ended, solvent weld.

B. Size of sleeve shall be a minimum of two pipe sizes larger than the pipe.

2.11 Backflow Devices

Backflow prevention devices shall be installed on all irrigation systems at the point of connection to the water source. Device shall include unions unless otherwise dictated by local codes. The device shall conform to all local codes and be installed as per manufacturer’s recommendations. All devices shall be approved by UPC, ASSE & AWWA, C-506. Installation must be performed by an individual or company licensed to do such work by the local governing authority.

2.12 Drip Components

Each drip zone shall include an electric valve, pressure regulator and filter.

A. Filter shall be in-line model constructed of noncorrosive material. Screen or disc shall be sufficient to eliminate debris and particulate matter as required (120 mesh or 75–600 microns). Size based on manufacturer’s recommendations with an operating pressure from 20–140 psi.

B. Pressure regulators shall be in-line type constructed of noncorrosive materials and capable of handling designated flow at discharge pressure indicated on drawings.

C. Emission devices shall be constructed of noncorrosive materials capable of delivering measured volumes of water to designated areas. An emission device shall be classified as:

1. Single emitter

2. Multi-outlet distribution manifold

3. Polyethylene tubing manufactured with in-line pressure emitters

4. Micro-spinner or spray

5. Pressure-compensating, self-flushing and having an integral check valve

D. Drip staples shall be minimum 11 gauge with U-shaped top. Square-top staples shall not be used.


E. Fittings shall be insert or compression type and shall not require clamping below 45 psi.

2.13 Pumps

A. Provide pump with capacity, total dynamic head, and electrical characteristics, as noted on drawing.

B. Pump enclosure, if applicable, as noted on drawing.

C. Pump fittings as per drawing details and as recommended by pump manufacturer.

D. Pump start relay, flow switch, pressure transducer, pressure switch, or other control devices, as recommended by pump manufacturer.

3.0 Execution3.1 Site Reviews

A. Before any work commences, a conference shall be held with the owner’s representative and contractor to discuss general requirements of the work and coordinate the installation process.

B. The contractor shall examine surfaces for conditions that could adversely affect execution, permanence, and quality of work. The contractor shall also verify that grading has been completed and that the work of this section can properly proceed.

1. Notify the owner’s representative in writing, describing unacceptable conditions.

2. Do not proceed with work until unacceptable site conditions are corrected.

3. Locate existing utilities.

C. The contractor shall notify the owner’s representative in writing for the following reviews, allowing 48 hours for compliance by the owner’s representative.

1. Submittal review.

2. Pressure supply line installation and testing.

3. Final review at substantial completion.

D. The contractor shall provide radio communication, remote control, and/or personnel to maintain communication from the review area to automatic controllers.

E. The contractor shall provide up to date “as-built” drawings and acceptance forms for authorized signature.

3.2 Utility Services

The contractor shall make connections to the provided power and water sources at locations indicated on

drawing(s) and make any minor changes in location as may be necessary due to actual site conditions. As necessary, authorized, licensed trade professionals shall be used to conform to local codes.

3.3 System Layout

A. All piping and equipment is shown diagrammatically on drawing(s).

B. Lay out sprinkler heads and make any minor adjustments required due to differences between actual site conditions and the drawings. Minor adjustments shall be maintained within the original design intent.

C. Lay out each system using staking method, as approved by owner’s representative.

3.4 Pipe Installation

A. Pipe assembly (PVC)

1. Pipe shall be sized so that the water velocity in pipe shall not exceed five (5) feet per second.

2. Routing of all irrigation lines as indicated on the drawings is diagrammatic. Install lines (and various assemblies) to conform to details provided on drawing(s).

3. Pipe shall be kept free of dirt, rock, shavings, and other debris. Pipe ends shall be cut square and true with either a saw or pipe-cutting tool. When a saw is used, shavings must be removed from pipe ends.

4. Use primer and solvent to join pipe and fittings in a manner recommended by the solvent manufacturer regarding pipe size, air temperature and humidity. Allow pipe connections to cure as per solvent manufacturer’s recommendations before pressurizing pipe. Wipe all excess glue from pipe after joint is made.

5. Service tees and service elbows installed in piping shall be oriented so FIPT outlet is on side of pipe.

6. Gasketed connections shall be installed per manufacturer’s recommendations.

7. Thrust blocks or joint restraints shall be provided for gasket pipes.

Thrust blocks or joint restraints shall be provided whenever PVC pipe:

a. Changes directions.

b. Stops (as at a capped end).

c. Joins a valve where thrust may be expected.


Thrust blocks shall be made of concrete and are to be installed between the fittings and undisturbed soil of the adjacent trench wall in accordance with current ASAE recommendations. Pipe and fittings shall be protected from concrete by wrapping in polyethylene film or fabric cloth.

8. Threaded fittings shall be assembled as follows:

a. Using Teflon tape applied to male threads only. No more than two wraps.

b. Using metal female adapters with schedule 80 PVC nipples as transitions.

c. Do not use schedule 40 female adapters except for swing pipe connections.

B. Copper pipe shall be installed as required by local plumbing codes. Underground copper lines shall be type “K” soft copper tubing. Depth of bury shall conform to this specification. Aboveground copper shall be type “L.”

C. Polyethylene pipe may be used only on residential lateral lines that are not under constant pressure.

1. Connections to insert fittings shall be installed over barbs. Pipe shall extend beyond the last barb on the fitting. Install two clamps per joint directly over barbs on all connections.

2. Internal double ‘O’ ring connection fittings may be used that have an integral lock mechanism and a minimum 400-psi burst rating.

3. Saddles used for service tees must be all plastic and have a locking mechanism to hold in place during on/off cycles and freeze/thaw cycles.

4. All mainlines shall be pressure tested. See section 3.19.

3.5 Trenching

A. Excavate trenches to required depths. Follow approved layout for each system.

Maintain bottom of trenches flat to permit all piping to be supported on an even grade for entire length of run, with recesses as required for pipe bells.

B. The minimum depth of soil cover shall conform to local codes, or shall be as shown or listed in the drawings, details, or specifications. Generally accepted practice is as follows:

Pressure Lines Non-Pressure Lines

InLandscaping

Under Vehicular

Paving

InLandscaping

Under Vehicular

Paving

Residential 12” 18” 8” 12”

Commercial 18” 24” 12” 18”

C. Sleeves under walks shall be at a 12" depth. Sleeves under drives and parking lots shall be at an approximate 18" depth. Sleeves under roadways should be at an approximate 36" depth, or as mandated by governing authorities.

D. Pipe “plowing” may be permitted by the owner’s representative in favorable soil conditions. When plowing is permissible, depth of pipe shall be the same as for trenching.

3.6 Backfill

A. The first 6" of backfill material shall be free of rock or foreign matter 2" in diameter or larger and hand tamped. The remainder of backfill shall be laid-up in maximum 6" lifts and tamped to a dry density equal to adjacent, undisturbed soil until the finish grade is reached.

B. When more than one pipe is installed in the same trench, separate pipes with a minimum 2" of soil.

C. Disturbed grade shall be restored to be free of dips, depressions, humps, or other irregularities. Compaction by truck or other vehicle is not acceptable.

3.7 Existing Pavements

A. Piping under existing pavements may be installed by jacking, boring, or hydraulic driving, except as otherwise specified or directed. For minimum depths, install pipe at a depth equal to 12" per inch of diameter of bore below finished grade.

B. Secure owner’s permission prior to cutting or breaking existing pavements. Refer to section 3.5 for minimum depths.

C. At locations where cutting is approved, make all cuts clean using power saws. Make cuts at approved locations only.

D. Replace and restore all disturbed surfaces to match adjacent undisturbed conditions, including grades and landscaping.

3.8 Automatic Valves and Valve Boxes

A. Automatic valves shall be installed plumb within valve access box with all handles, bolts, connections, and electrical splices accessible through the valve box opening.


B. Clearance between the highest part of the valve and the bottom of the valve box lid shall be 2" minimum and 18" maximum.

C. Clearance between the valve body and the sides of the valve box shall be a minimum of 3". Clearance between the valve bodies shall be a minimum of 2". Valves shall not be “stacked” within a valve box.

D. Valves or valve boxes shall not be installed within 12" of paving or structures.

E. The valve box shall be supported so that it does not rest directly on any irrigation piping.

3.9 Control Wiring

A. Control wiring shall be installed as follows:

1. When in common trench with mainline, wiring shall be laid beside or at the same invert as the mainline.

2. Use minimum number of splices, and make all splices in valve or splice boxes. Splice connectors shall be UL approved for direct bury.

3. Provide 24" expansion coils at all valves and at 300’ intervals between valves and directional changes. Wire shall at no time be installed taut.

4. Tape, or cinch with cable cinches, wires at maximum of 25’ intervals.

5. Aboveground wire is to be installed in conduit and/or in accordance with electrical codes.

6. Common, or neutral, wire shall be WHITE on single or multi-conductor wire. If single conductor wire is used, valve wires and spare wires shall be of a different color consistent throughout the system.

7. Valve wiring shall be the same color from controller to valve.

8. Two wire control systems shall use wire approved by controller manufacturer.

9. Grounding wire shall be single-strand, solid, bare copper, at least two wire gauges larger than largest control wire used in the system.

3.10 Sprinkler Heads

A. Sprinkler heads shall be set perpendicular and flush to grade or at elevations noted on the drawings.

B. Pop-up heads shall be set 4" from paved surfaces. Rigid risers shall not be permitted adjacent to paved surface or other traffic areas.

C. All heads shall be tested to verify proper coverage. See section 3.20.

D. Connections to piping:1. Flex pipe may be used for heads with flows of 6

gallons or less. Pipe length shall be a minimum of 1 foot and a maximum of 4 feet.

2. For flows over 6 gallons per minute and on all sports fields, pre-fabricated triple ‘O’ ring swing joints shall be used. Swing joint size shall match head inlet. Lay length shall be such as to allow a 30–45 degree angle from pipe to lay nipple.

3.11 Quick-Coupling Valves

A. Quick-coupling valves: Install downstream from backflow preventer on a swing joint assembly. When installed as a blowout connection, install as close to the point of connection as possible.

B. Install quick coupler valve in a 10" round valve box at a depth that will allow quick coupler key to turn freely when inserted.

C. A swing joint manufactured for use with quick couplers shall be used to connect valve to piping. A swing joint shall, as an integral brass male threaded nipple matching the inlet size of the valve, have the ability to be stabilized and have the proper lay length to allow for a 30–45 degree angle from the pipe to lay riser.

3.12 Drain Valves

Manual: Install at low points on main and laterals when specified. Provide valve box for access and 2 ft3 gravel sump with soil separator.

3.13 Drip Irrigation

A. Six-inch (6") soil staples shall be placed every 3’ on tubing and at every elbow, tee, and cross if tubing is installed on soil below mulch. Staples not required if tubing is buried.

B. Tubing shall be installed below mulch layer in plant beds or buried up to a 4" depth. Tubing in turf shall be installed at a uniform depth of 4".

C. Each zone shall have a supply and exhaust header sized so total flow does not exceed 5 feet per second.

D. In-line emitter tubing dripper interval and row spacing shall be as recommended by manufacturer, taking into account plant type, soil type, slope, and emitter flow rate.

E. In-line emitter tubing shall be installed as a looped grid system.

3.14 Sleeves


A. Sleeves are to be installed beneath all paved surfaces as indicated on the drawing. Installation is to be coordinated with project general contractor.

B. If sleeves are to be installed by others, an accurate as-built drawing is to be provided to the irrigation contractor prior to the commencement of work. The end of the sleeves shall be indicated with a visible marker.

C. Wiring shall be installed in an individual sleeve, separate from sleeves designated for piping. A wiring sleeve may be installed within a larger sleeve containing other irrigation pipe.

D. The size of a sleeve shall be a minimum of two pipe sizes larger than the pipe enclosed.

3.15 Controller

A. Controller shall be located as generally noted on the plans in an accessible location. Controller should be level and properly anchored to the wall, or in the case of a pedestal, version to a concrete pad.

B. Zones shall be ordered as directed on the plan or in consecutive geographic order.

C. Controller shall be grounded per manufacturer’s recommendations.

D. Wiring inside controller shall be neat with external jacket of wire (multi-strand and two-wire) removed.

E. Control wire shall be installed inside conduit from below grade to controller cabinet.

F. Zone charts as described in Section 3.22 shall be left at controller location.

3.16 Sensor Devices

A. A rain sensor shall be installed in an area exposed to direct rainfall but out of sprinkler coverage.

B. Sensor wires shall not be spliced and shall terminate inside controller at sensor terminals.

C. All devices shall be installed per manufacturer’s recommendations.

3.17 Decoders (Two-Wire Only)

A. Decoders shall be from the same manufacturer as the controller.

B. Decoders shall be located in valve boxes for service access. Decoders shall be mounted to sides of valve boxes.

C. Connections to two-wire path shall be made with UL-approved, direct bury splice kits rated for submersion.

3.18 Surge Arrestors (Two-Wire Only)

A. Arrestors shall be located in valve boxes.

B. Arrestors shall be grounded to rods/plates per manufacturer’s recommendation following ASIC standards.

C. Arrestors shall be installed at distances and locations on two-wire path as recommended by manufacturer.

3.19 System Flushing

A. All mainlines shall be flushed prior to testing.

B. After all pipe and flexible risers have been installed, and prior to the installation of control valves and sprinkler heads, thoroughly flush all lines with a full head of water.

3.20 Pressure Tests

A. If required by owner, the contractor shall provide all equipment to test the system, including a force pump.

B. All mainlines under constant pressure shall be filled with water at designated pressure for at least 24 hours and proven tight by visual inspection. The system shall then be tested under hydrostatic pressure of 150 psi for a period of two hours, unless otherwise approved. Leaks shall be repaired and the system shall again be flushed and retested.

3.21 Adjustment

A. Install sprinkler bodies and nozzles. Adjust radius and arc for optimum performance. Make any necessary adjustments in head locations to achieve 100% coverage of landscaped areas designated to be watered.

B. Adjust flow controls and pressure-reducing valves to attain the required pressure for optimum performance at the sprinkler head.

3.22 Coverage Test

A. After sprinkler system is completed, test the system to ensure that all lawn and planting areas are watered completely and uniformly.

B. Make any necessary adjustments as required by the owner’s representative to provide proper coverage.

3.23 Operating and Maintenance Tools

A. The following items shall be delivered to the owner when work is completed and prior to final acceptance of work.

1. Two keys for each automatic controller.

2. Two sets of any specialty adjustment or disassembly tools required for each type of sprinkler head supplied.


B. The following items shall be delivered to the owner if applicable to the system.

1. 30" valve keys for operation of manual drain valves

2. Two keys for opening lockable valve boxes

3. One 72" steel tee wrench for operating gate valves with square nut

4. One 72" steel tee wrench for operating bar handle stop and waste valve

5. One (1) quick-coupler key per three (3) quick couplers with matching swivel hose L’s

C. Provide owner instruction in operation of system.

D. Provide zone charts to owner that include:

1. Zone geographic location

2. Head type

3. Type of landscape covered

4. Required run time

3.24 Cleanup

Upon completion of all work, the contractor shall restore all ground surfaces disturbed during the irrigation installation to their original condition to the satisfaction of the owner’s representative. Remove all excess irrigation material, waste, debris, and equipment from the site.

6th edition


Non Tidal Wetland Planting

Landscape Specification Guidelines 1 Non Tidal Wetland Planting


A. The landscape contractor shall provide all materials, labor, and equipment required to complete all wetland planting work as shown on the plans and specifications.

B. Plant quantities, size, spacing, and condition shall be stated on the Wetland Planting Plan. The plant list submitted with the bid will automatically become part of the contract documents.

C. The landscape contractor shall bid according to the plant list. It is the wetland designer’s responsibility to be sure that the plant count is correct, and that each plant grouping is clearly labeled on the plan with the total number of plants per grouping shown.

D. If applicable, the owner shall provide to the landscape contractor a copy of all wetland permits and an approved wetland mitigation plan or an approved letter together with the mitigation plan.

1.2 Standards

A. All plant material should be indigenous to the eastern region of the United States and grown within the same USDA Hardiness Zone as the wetlands site.

B. Container-grown, bare root, and seedling tree and shrub plant material shall conform to the current issue of the American Standard for Nursery Stock, published by the American Nursery and Landscape Association.

C. Collected material may be used only when approved by the wetland designer, owner, or owner’s representative.

D. Nomenclature will be accordance with the most recent edition of Reed, P.B. Jr., National List of Plant Species that Occur in Wetlands: Northeast (Region 1). U.S. Fish and Wildlife Service. Biol. Re. 88 (26.1).

E. It is the wetland designer’s responsibility to specify the need for “wet-cultured” plant material. If “wet-cultured” plant material is specified by the wetland designer, the material shall be grown in a saturated soil condition for a minimum of three months during the growing season. Otherwise, wetland plant material is not required.

1.3 Wetland Plant Availability

Wetland plant species are not always readily available in quantity. It is the landscape contractor’s responsibility to verify the availability of specified plant material for the

appropriate planting season and construction schedule. Often if large quantities of one wetland plant species are required, the material will have to be contract-grown. A list of potential plant suppliers may be provided by the wetland designer or listed on the Wetland Planting Plan for the landscape contractor’s use.

If plant materials are to be collected from the wild, any requisite permits must be obtained from appropriate government agencies regulating such collection. Collection may not be acceptable in some areas due to the potential damage to the natural wetland environment. If circumstances exist where collection is appropriate, digging should be done by hand in such a way as to minimize visual and physical impact to the site, and be in a staggered fashion to avoid mutilation of large areas of wetland. See Section 2.2 for details on handling and storage of collected plant material.

1.4 Approvals


1.5 Substitutions: Pre-Bid

It is the landscape contractor’s responsibility to make every reasonable effort to find the material specified by the wetland designer. The landscape contractor is responsible for qualifying his/her proposal to document any plant suitability or availability problems. It is the landscape contractor’s responsibility to provide a list of proposed plant substitutions in the bid response for the wetland designer’s approval. The contractor shall submit a base bid as per plan, plus price clarifications for all recommended substitutions.

1.6 Substitutions: Post-Bid

If a substitute is selected, it must be approved by the owner’s representative prior to award of contract.

It is the intent to eliminate post-bid plant substitutions. However, in the event that the contract material has become unavailable, the owner’s representative must approve an appropriate substitution.

1.7 Utilities

A. It is the landscape contractor’s responsibility to notify utility companies and/or the general contractor in advance of construction to locate utilities (www.missutility.net for MD, DC, and DE or http://va811.com for VA).

B. If there is a conflict with the utilities and the planting, the wetland designer shall be responsible for relocating plants prior to the planting process.



The landscape contractor shall not be liable for delays in planting, relocating plants, or damage to plants resulting from undisclosed, subsurface conditions such as, but not limited to, rock, clay pan, or soils contaminated with toxic substances or other obstacles encountered in excavation work that are not apparent at the time of estimating.

1.9 Unsuitable Conditions

If plants are specified to be planted in conditions that would be detrimental to growth and/or plant survivability as determined by the landscape contractor, the landscape contractor shall notify the wetland designer or owner’s representative. If the wetland designer concurs with the landscape contractor’s assessment, any associated costs due to the relocation of the plants or other site modifications will be at additional cost to the owner.

1.10 Soil Testing

Unless otherwise noted in the plans or specifications, the wetland designer prior to plant selection should conduct a soil test, and if soil amendments are required, type and quantity shall be identified in the bid package. The soil test shall be performed for the soil that will be exposed following excavation, or for whatever soil will be used as the growing medium.

1.11 Workmanship

A. During delivery and installation, the landscape contractor shall perform in a professional manner and leave the work areas clean of litter and debris at the close of each workday.

B. During planting, all areas shall be kept neat and clean, and precautions shall be taken to avoid damage to existing plants, trees, erosion and control devices, and structures (e.g., water-control structures, headwalls, aprons). If a limit of disturbance boundary is delineated in the field, this line must be adhered to diligently.

C. Upon completion of planting operations, the landscape contractor shall remove all debris and waste material resulting from planting from the project area, at his/her expense, and restore any areas damaged by his/her equipment and workers.

1.12 Water Supply

The owner shall supply water on site at no cost. If the landscape contractor has to supply the water or watering equipment to the site, it shall be at an additional cost to the owner.

1.13 Planting Seasons

The recommendations below are only general guidelines. There are many other factors that play a role in determining whether a plant will survive. Planting may need to be delayed to accommodate soil conditioning procedures or the removal of invasive species at the planting site. Wetland permits often contain planting windows.

A. A Planting shall not occur if the ground is frozen.

B. Tubers, sprigs, bulbs, and rhizomes must be transplanted before new growth emerges. Therefore, they are best planted in the fall after dormancy, or in the winter before dormancy breaks.

C. Most of the sedges and grasses are best planted immediately after dormancy breaks in the spring.

D. Woody and herbaceous peat-potted/container nursery stock may be planted at any time of the year, including plugs. All woody material shall be hardened off or fully dormant when planted.

E. It is recommended that woody plant species be planted in the fall or early winter, after the onset of dormancy. However, if winter flooding is anticipated, species selection and water level management are crucial to seedling survival.

F. Growing bare root and field-collected plugs shall be planted during the early growing season.

G. Bare root trees and shrubs are to be installed while dormant when weather allows.


A. Inspection: An onsite inspection of the work identified in the contract documents is to be conducted by the wetland designer and owner or owner’s representative in the presence of the landscape contractor for the purpose of acceptance. Inspection shall be made within two weeks of written notification from the landscape contractor. Failure of the owner to inspect the work shall void the landscape contractor’s guarantee. During inspection for initial acceptance, the landscape contractor shall have an acceptance form to be signed by the owner or the owner’s representative.

B. Initial Acceptance: There should be an approval of the work inspected. Acceptance can be on partially completed work under the contract, if approved by the wetland designer or owner. If, for reasons beyond the landscape contractor’s control, work has stopped, inspection shall be made on partially completed work. Warranty shall begin after landscape inspection and acceptance. Maintenance


after initial inspection and acceptance shall be the responsibility of the owner, unless an optional maintenance contract has been specified.

1. The landscape contractor shall periodically inspect the site during the warranty period and notify the owner in writing if proper maintenance is not being performed.

C. Final Inspection and Acceptance: The landscape contractor shall conduct a final inspection with the owner or owner’s representative at the end of the warranty period.

1.15 Warranty

A. The term and extent of the warranty for wetland plant material usually differs from that of upland balled and burlapped plant material, since site conditions are not as predictable. A warranty period shall be agreed upon between the owner and landscape contractor for each individual wetland planting project, and made a part of the contract documents.

B. The warranty shall commence on the date of initial acceptance by the owner or owner’s representative.

C. All plants listed in the warranty shall be in satisfactory health at the end of the warranty period.

D. Warranted plant material that is 25% dead or more shall be considered dead and must be replaced at no charge. A tree shall be considered dead when the main leader has died back, or if 25% or more of the crown is dead.

1.16 Replacements and Conditions

A. Plant replacements shall be made during the next appropriate planting season unless the landscape contractor agrees to an earlier date.

B. The landscape contractor shall be responsible for a one-time replacement only.

C. Replacement plants shall be of the same size and species as the original, and fertilizer and backfill mixture the same as originally used, unless specified otherwise by the wetland designer. If replacement plant material is not identical to the original material at the request of the wetland designer or owner, the difference in cost will be borne by the owner.

D. The landscape contractor will not be responsible for plant material that has been damaged by vandalism, fire, removal, relocation, animal predation, or other activities beyond the landscape contractor’s control.

E. Collected and transplanted materials are not guaranteed, unless agreed to otherwise in contract documents.

F. The landscape contractor will not be responsible for plant losses due to abnormal weather conditions such as floods, excessive wind damage, drought, severe freezing, or abnormal rains.

1.17 Maintenance

If the owner or wetland designer desires maintenance, the details should be outlined in separate Specifications and made a part of the contract documents.

2.0 Plant Materials2.1 Scope of Work

The landscape contractor shall be responsible for supplying and installing all plant material represented on the Wetland Plant Schedule as submitted with the contract. The landscape contractor shall have investigated the sources of supply and satisfied himself/herself that he/she can supply all the plants specified in the Plant Schedule in the size, variety, quality, quantity and condition stated or as specified in the contract. Failure to take this precaution will not relieve the successful bidder from the responsibility for furnishing and installing all the plant material in strict accordance with the contract requirements and without additional expense to the owner.

2.2 Standards

All material shall be nursery-grown unless otherwise specified.

A. Bare root seedlings and older plants (woody)

1. Bare root trees and shrubs shall be dug with adequate, well-developed fibrous roots, pruned to a length of approximately 8" to ease planting, if the pruning does not result in more than 25% of the root system being removed.

2. Seedlings shall have a minimum top length of 18".

3. The diameter of the root-collar shall be at least 3/8".

4. Plants shall have an abundance of well-developed terminal buds on the leaders and branches.

5. The stems and branches of all plants shall be turgid and the cambium healthy.

6. Plants that are in leaf or that show signs of leafing out shall not be acceptable.

B. Growing bare root plants (herbaceous)


1. Plants shall show new roots that are clean and white in coloration.

2. Plants shall appear healthy with no foliage spots, discolorations, wilting, or other evidence of the presence of disease or insect damage.

C. Container-grown stock (woody and herbaceous)

1. Plants shall be in accordance with the current issue of American Standard for Nursery Stock, published by the American Nursery and Landscape Association.

2. The root system of container-grown plants shall be well-developed and well-distributed throughout the container, such that the roots visibly extend to the inside face of the growing container.

3. If in leaf, the plants shall appear healthy with no leaf spots, leaf damage, leaf discoloration, leaf wilting or evidence of insects on the plant.

D. Peat-potted nursery stock (herbaceous)

1. Peat-potted nursery stock shall be contained in 13/4" to 21/4" pots.

2. Each pot shall contain at least four stems having a minimum of 6" of active growth.

3. Roots shall be sufficiently well-developed through the peat-pot surfaces so that plants are firmly contained in the pot.

4. If growing, the plants shall appear healthy with no leaf spots, leaf damage, leaf discoloration, leaf wilting, or evidence of insects on the plant.

E. Plugs (herbaceous, woody seedling, or rooted cutting)

1. The width and depth of plugs shall be at least 4" for grasses, rushes, and sedges.

2. Plugs shall have a solid soil/root mass with the soil in place. Roots shall appear clean and white in coloration.

3. If growing, the plants shall appear healthy with no leaf spots, leaf damage, leaf discoloration, leaf wilting, or evidence of insects on the plant.

4. If dormant, new healthy shoots (herbaceous) shall be apparent, or stems (woody) shall be supple and exhibit a healthy cambium.

5. Plugs (herbaceous) containing shoots that are soft or mushy or otherwise appear rotten and plugs (woody) containing brittle stems or having unhealthy cambium shall not be accepted.

F. Un-rooted cutting

1. Hardwood cuttings (whips) shall be 30–55 cm long and between 8 and 13 mm in diameter.

2. The cuttings must be alive, fresh, and with bark intact.

3. Cuttings should have at least two bud scars near the top to facilitate development of branches.

4. The larger or thicker butt ends should be cleanly cut at a 45 degree angle for easy insertion into the soil, and the top should be cut square or blunt.

G. Dormant propagule (herbaceous): These may be bulbs, tubers, or rhizomes.

1. Propagule shall be a single stem (culm) of grasses or sedges and associated roots, basal shoots, and any short rhizome sections left intact. Old or new top growth should be clipped to a length of 6 to 12".

2. Bulbs and tubers shall be hard.

3. Rhizomes shall be resilient.

H. Collected plant material

1. Excavated material shall meet the above requirements for the appropriate condition, at a minimum. Plants should be transported and replanted within 24 hours. The plants must be kept moist and protected from the wind during transport.

2.3 Inspection

A. Plants may be subject to inspection and approval by the owner or owner’s representative at the place of the growth for conformity to specification requirements as to quality, size and variety. It is the landscape contractor’s responsibility to know his/her sources. Costs of inspection visits shall be borne by each individual party.

B. Plants damaged in handling or the owner may reject transportation or improper storage or owner’s representative on-site.

C. Plants with excessive soil above the root flair may be rejected by the owner or owner’s representative on-site.

D. Any plant material inspected at the place of growth, accepted and sealed by the owner’s representative that has not been damaged during transportation or handling or has not been improperly stored, cannot be rejected at the site.


2.4 Plant Transport, Handling, and Storage

A. Plants shall be transported in a covered vehicle, and if the weather is very hot, protected from the heat.

B. Plant material shall not be exposed to high winds.

C. Large quantities of plant material shall be shipped by express packing source, picked up by the landscape contractor, or delivered by the supplier.

D. Large quantities of plant material shall be shipped as several partial shipments in quantities that match planting rates to reduce onsite storage requirements and limit plant mortality.

E. All plants shall be stored in a cool, shaded environment and watered routinely so that the soil and roots are kept moist at all times until planting.

F. Preferably, bare root seedlings shall be planted immediately. Otherwise, bare root seedlings shall be stored, still wrapped, in a cool, dark place, ideally a cold- storage unit set at 34 to 39 degrees Fahrenheit. However, an enclosed structure will suffice for a few days if the roots are not allowed to dry out or freeze.

G. Cuttings shall be fresh and must be kept moist. Cuttings should not be stored more than one day before planting; to increase the rate of survival, they should be planted the same day.

H. The root system of emergent species shall be kept in water or in contact with a saturated mulch material.

I. If plugs are not shipped in a growing container, and will not be planted immediately, root masses shall be protected by covering them with straw, compost, or other suitable material.

J. Floating-leaved and submerged aquatics must be kept continuously wet and are best transported in water. They shall not be stored more than a day or two. The wetland designer shall specify if frequent water changes are necessary.

3.0 Products3.1 Quality Assurance

Manufacturer’s certified analysis shall accompany packaged standard products.

3.2 Organic Matter

A. Leaf mold – thoroughly shredded, well-composted leaf material, free of trash.

B. Pine bark – potting-grade pine bark screened through a 3/4" screen and containing less than 10% sap wood fibers. Any pine bark containing more

than 10% sapwood must be composted through the first heat stage.

C. Peat Moss – Type 1 sphagnum peat moss; finely divided with a pH of 3.1 to 5.0.

3.3 Topsoil

The practice of over-excavation and then backfilling with topsoil for wetland creation projects are usually not necessary. Most substrates will support the establishment of vegetation. Exceptions to this would be gravel or bedrock and dense clays, as well as soils that contain toxic materials or high or low pH readings. A medium texture soil, with 20% to 35% clay or organic matter is considered an ideal soil medium.

If wetland soils are to be used for topsoiling—“mucking”—then the wetland designer shall provide separate specifications for the procedure of stripping, storing, or stockpiling; maintaining; and spreading of the wetland soil. If this method is specified, the host soil should be tested before stripping to evaluate the species in the seed bank, in order to check for the presence of invasives.

3.4 Fertilizer

Perform a soil test to determine nutrient requirements. Apply fertilizer based on soil test results and recommendations in accordance with current Department of Agriculture regulations or applicable jurisdictions.

3.5 Backfill Mixture

A. The planting of herbaceous plant material does not normally require soil amendments.

B. Backfill mixture for trees and shrubs shall be equal parts of existing soil and organic material, plus fertilizer. Assuming that the planting hole is approximately twice the size of the plant container, the following equation may be used to estimate the amount of compost required:

(# of plants)(Ctr. size in gal.)(0.005) = # of cubic yards of compost

C. If any other additives are found to be necessary at the time of planting, it shall be with the approval of the landscape contractor, wetland designer, and owner or owner’s representative at an additional negotiated cost.

3.6 Stakes

Stakes shall be 2"x 2" hardwood or acceptable equivalent. See section, 5.7, Tree Support Schedule in the Exterior Landscape Installation specification for proper stake length.


3.7 Guying Material

A. Wire: Wire shall be 12 or 14 gauge galvanized steel or acceptable equal, depending on size of tree. See section 5.7, Tree Support Schedule of the Exterior Landscape Installation specification.

B. Non-wire tie: Flat, woven, smooth, elastic tie material (e.g., ArborTie®)

3.8 Hose

Hose shall be corded rubber, uniform in color, and either 1/2" or 3/4", depending on the size of the tree. Other methods such as straps or plastic chain locks may be used where acceptable. See section 5.7, Tree Support Schedule of the Exterior Landscape Installation specification.

4.0 Soil Preparation4.1 General Conditions

If the planting area is covered with a temporary cover crop of invasives, this growth must be eliminated at the expense of the grading contractor or owner. Work shall proceed only after rough grading has been completed and the sub grade is within the specified grading tolerances in the contract documents or plan.

4.2 Topsoil Installation

If topsoil installation is necessary, the wetland designer shall provide separate specifications.

4.3 Tilling

After the planting area has been brought to grade, the substrate shall be deconsolidated by disking, ripping, plowing, or tilling to a depth of 4" to 6". If deeper deconsolidation is required by the wetland designer (e.g., for woody areas), it shall be specified on the plans or in the contract documents.

4.4 Acceptance

Acceptance for soil preparation shall be given by the wetland designer upon satisfactory completion of each section or area as indicated on the drawings or as otherwise specified in the field. Installation by the landscape contractor prior to said acceptance by the wetland designer indicates acceptance of soil by contractor.

5.0 Final Grading5.1 General Conditions

The landscape contractor shall proceed only after

the topsoil or subsoil has been prepared uniformly in the designated areas to within the specified grading tolerances in the contract documents or plan. Any undulations or irregularities in the surface resulting from fertilizing, tilling or other causes shall remain to provide a beneficial micro- topography throughout the site. Flooded, washed out or areas otherwise damaged shall be reconstructed and all grades re-established by the landscape contractor in accordance with the drawings and/or as specified by the construction supervisor in the field.

5.2 Cleanup

Prior to planting and/or seeding, the surface shall be cleared of all trash, debris and stones larger than 11/2" in diameter or length, and of all roots, brush, wire, grade stakes, and other objects that would interfere with planting or seeding operations.

5.3 Acceptance

The onsite construction supervisor, upon completion of each planting section, shall give acceptance for final grading or area as indicated on the plan or as otherwise specified. Final grade shall be within the specified grading tolerances in the contract documents or plan.

5.4 Maintaining the Final Grade

The grading contractor shall be responsible for maintaining the final grade in the accepted areas that are to be planted or seeded until the effective date to begin planting or seeding operations. The effective planting or seeding date shall be specified in a written notice from the grading contractor or owner.

6.0 Planting Procedures6.1 Planting Procedures for Container-Grown

Material

A. Remove the plant either by cutting or inverting the container.

B. Use a knife or sharp blade to make four to five 1" cuts the length of the root ball; loosen the roots from the outside of the rootball.

C. A pit shall be dug large enough for the proper setting of the rootball (1’ wider than the root ball) and deep enough to allow 1" to 2" of the rootball to set above existing grade. Plants from flat-bottomed containers shall not be planted in V- shaped pits, such as produced by a dibble bar or pointed spade.

D. Set the plant straight and in the center of the pit.


E. Use a backfill mixture and fertilizer as specified in Section 3.5 and 3.4, respectively.

F. Backfill the sides of the pit with soil mixture and tamp firmly as the pit is being filled.

G. Make sure the plant remains erect during the backfilling procedure. Trees shall not have more than a 10% lean following backfilling.

H. Leftover soil from the planting pit excavation shall be raked around the plant, being careful not to alter the existing grade significantly. A saucer shall not be formed around the plant.

I. Water the plant thoroughly until the soil is saturated, even if it is raining.

J. Remove all tags, labels, strings, etc. from the plant.

6.2 Planting Procedures for Bare Root Material

A. The pit shall be only broad enough to accommodate the roots fully extended and only deep enough so that the uppermost roots will be just below the original grade.

B. Set the plant in the pit so that all roots, when fully extended, will not touch the walls of the planting pit and the uppermost roots are just below the original grade. Seedlings should be planted erect.

C. Spread out the roots properly and work backfill mix among them. Prune off broken roots in a natural position. Water thoroughly while backfilling.

D. The plant shall be heeled into the ground, firmly packing the soil around the roots.

E. Complete the planting process as outlined above in section 6.1 E through J.

6.3 Planting Procedures for Unrooted Cuttings

A. Tamp the cutting into the soil in an upright position, with buds up, and no more than half of the total length of the cutting above ground.

B. Soil shall be firmly packed around the cutting.

C. Do not split the cutting during tamping.

D. An iron bar can be used to make the hole; tamping is best accomplished with a dead-blow hammer (i.e., a hammer with a hollow head filled with shot).

6.4 Planting Procedures for Propagules

A. Whole plants shall be installed with the root down.

B. Plant to a depth that allows the root collar, evidenced by a dark line or a line dividing two color zones, to be flush or slightly above existing grade.

C. Either hand planting or a tree planting bar or tile spade may be used to make a slit in the substrate, insert the propagule, and firmly pack the soil around the propagule.

6.5 Planting Procedures for Peat-Potted Plant

A. Using a trowel or similar digging equipment, dig a hole large enough to accommodate the potted plant, while allowing space to backfill around it.

B. Crush, crumble, slice, or otherwise attempt to disjoin the peat pot before planting in order to speed up decomposition of the peat pot.

C. Place the plant in the hole so that the top of the soil ball is even or slightly higher than the surrounding grade.

D. Complete the planting process as outlined above in section 6.1 E through J.

7.0 Seeding Procedures7.1 Products

A. For purposes of stabilizing and establishing side slopes or areas where standing water or moving water are not to occur, the following may be applicable:

1. Mulching materials

a. Straw shall be bright in color, free of rot and mildew, small- grained, free of all noxious weeds.

b. Cellulose fiber: Cellin-K, recovered cardboard, is the preferred type for hydro-seeding because of ease of incorporation into slurry. Cellin, recovered newspaper.

2. Stabilizing materials

a. Chemical tacking

b. Twine: binder twine used for small areas.

c. Netting: nylon netting used with metal staples or wooden pegs.

d. Crimping: mechanical, tractor-drawn implement for stabilizing mulch.

e. Cellulose fiber: as detailed above.

7.2 Standards

A. Collected seed should only be used when approved by the owner’s representative and wetland designer.

B. The supplier of the seeds shall supply the germination test results (within the last three


months) and the percent purity of the seeds upon delivery to the site. Specifications should indicate seeding rates using pure viable seed. All seed must be cleaned, processed, analyzed for purity, stored, and germination tested before being used. Every seed variety contains different germination rates and requirements, and it is the wetland designer’s responsibility to specify the germination requirements of the seed variety specified.

7.3 Seed Availability

Large quantities of various native seed species may not be available commercially unless they are collected from the wild. If specifications require the collection of seed from native (local) plant communities, caution should be taken not to exhaust the seed supply of that native plant community. Authorization from the appropriate agencies and property owners should be granted prior to collecting native seeds.

7.4 Related Work

1.10 Soil Testing3.3 Topsoil4.0 Soil Preparation5.0 Final Grading

7.5 Planting Season

Herbaceous seeds will have the best germination rate if planted in the fall or very early spring. Based on the seed requirements for germination, the seed may need to be planted in the late fall for stratification to occur. The seed may be manually stratified and planted in the beginning of the growing season if the wetland designer feels it is appropriate. The wetland designer shall specify the appropriate planting season for each individual seed species.

7.6 Seeding Procedures

A. The following are various seed applications that may be applied when sowing seed in the wetland mitigation areas. The wetland designer shall determine the method of seed application appropriate for the site.

B. It is important to evaluate the terms of suitability of the seeded wetland species to the site conditions. Before specifying the seed, the designer should consider the capability of performing a successful seeding and the suitability of the species for the site.

1. Aerial Seeding: Generally useful when applying seed to a very large area.

2. Broadcast Seeding: May be applied by hand or using equipment from the ground or boat.

3. Drill Seeding: For fine seeds, firm conditions are needed to attain the correct seeding depth. Plant the seed at the depth four times the diameter of the seed or based on seed requirements. Mulching or stabilizing is not necessary for this procedure.

4. Hydro-seeding: Often a slurry mix and useful when seeding steep slopes. Consideration should be given when applying within wetland areas, which may receive frequent water flow or experience ponding, as the water flow may wash the seed away or the seed and slurry may float away.

5. Wet Seeding: Seeds are soaked until they sink and then are broadcast. This process is only suitable for seeds that absorb water and can tolerate standing water to germinate and survive.

7.7 General Seeding Application

A. When seeding a cover crop for wooded or scrub shrub sites, if the planting of the woody species occurs first, care should be taken not to disturb the root mass of the tree or shrub. Otherwise, time should be given, if practical, for the cover crop to germinate and begin growth.

B. Prior to sowing, the finished grade shall be of a friable, non-compacted nature to ensure good soil to seed contact. The area may be deconsolidated through disking, roto-tilling, or ripping to a depth of at least 4" to 6".

C. Planting rows should traverse the narrow axis of the wetland mitigation area rather than the longer axis of the wetland mitigation area.

D. For smaller seeds (greater than 500,000 seeds per pound), dilute and mix with sand or cat litter to provide an even seeding distribution. Press the seed into contact with the final grade and cover with a thin film of silt or mud 1/8" thick.

E. Wet-stored seeds should be mixed with clay-based cat litter, dry sand, or other active dry agents to provide de-clumping of the seeds and suitable flow of the seed during distribution.

F. Larger seeds (less than 500,000 seeds per pound) should be subsurface sown to various depths depending on the size of the seed, unless the wetlands designer allows hydro-seeding. Larger seeds should not be pre-dried.

G. Apply 8- to 9-month release, 18-6-12, or comparable fertilizer at a rate of 300 pounds per acre.

H. Seeding applications shall occur using one of the methods specified above, ensuring that even coverage has been achieved.


I. If site conditions allow, seeding may be accomplished with a tractor and cultipacker. The cultipacker should be set to just scarify the sediments in order to avoid the placement of the seeds more than 1/8" deep. Traverse the site three times with the tractor using different patterns to ensure soil to seed contact.

J. Mitigation areas with water control structures should be maintained in a moist condition with less than 1" of standing water until seed germination is complete and the seedlings are 2" to 3" tall. Based on seed requirements, standing water deeper than 1" may be acceptable during the germination process.

K. Return the designed hydrology to the site that is appropriate for the seeding species.

6th edition


Seeding & Sodding

Landscape Specification Guidelines 1 Seeding & Sodding


A. The landscape contractor shall furnish all labor, material, and equipment required to complete the work described herein in strict accordance with the drawings and/or terms of the contract. All previously established grades shall be in conformance with the drawings and/or other specifications.


1.2 Submittals

When requested by the owner or owner’s representative, samples of all materials shall be submitted to the owner’s designated representative for approval.

1.3 Soil Testing

A soil test shall be made to determine soil texture, pH, magnesium, phosphorus and potassium. Additional tests for soluble salts and organic matter should also be made. Soil tests shall be conducted by a state laboratory or recognized commercial laboratory. The landscape contractor shall perform one (1) soil test using a representative sample of on-site soils. If existing soil has been undisturbed and is suitable as determined by soil test, no additional amendments are required. If the owner does not accept the soil test results as submitted by the landscape contractor, the owner is accepting full responsibility and thereby voids the landscape contractor’s guarantee. Adjustments should be made based on soil test results.

Acceptable Soil Test Results

pH range Bluegrass 6.0- 7.0, Fescues 5.5-7.0

Organic matter >1.5 %

Magnesium - Mg 35 pounds per acre

Phosphorus - P205 100 pounds per acre

Potassium - K20 85 pounds per acre

Soluble salts not to exceed 900 ppm

Refer to the Soils specification, section 1.7 Soil Testing, to determine how to raise and lower pH.

1.4 Workmanship

A. During sodding/seeding, all areas shall be kept neat and clean and precautions shall be taken to avoid damage to existing plants, turf and structures.

B. Upon completion, all debris and waste material resulting from sodding/seeding operations shall be removed from the project and the area cleaned up.

C. Any damaged areas caused by the landscape contractor shall be restored to their original condition.

2.0 Products2.1 Quality Assurance

Manufacturer’s certified analysis shall accompany packaged standard products.

2.2 Organic Matter

A. Sedge peat: Decomposed peat containing no identifiable fibers.

B. Leaf compost: Screened and free of trash.

C. Composted sewage sludge: Approved, screened, polymer-dewatered sewage sludge with a pH of 6.2 to 7.2.

D. MSW (municipal solid waste) compost with pH of 6.2 to 7.2 that is screened and contains less than 1% man-made materials.

2.3 Topsoil

A. Topsoil shall meet acceptable soil test levels as specified in the Soils specification. A certificate of soil test analysis must be submitted to the landscape architect for approval before any topsoil is delivered to the project.

B. Topsoil installed on grade shall attempt to match existing soil texture, except for situations where clay subsoil exists. Where clay subsoil exists, use loam or silt loam topsoils.

C. Topsoil shall be free of stones, lumps, plants, roots, and other debris over 11/2". Topsoil must also be free of plants or plant parts of Bermuda grass, Quack grass, Johnson grass, Mugwort, Nutsedge, poison ivy, Canada thistle, or others as specified.

D. Topsoil shall not contain toxic substances harmful to plant growth (e.g., pesticide residues).

2.4 Fertilizer

All fertilizers shall be uniform in composition, free flowing, and suitable for application with approved equipment. Fertilizers shall be delivered to the site fully labeled according to applicable state fertilizer laws and shall bear the name, trade name, or trademark and warranty of the producer. Applications shall be determined by soil test recommendations.

2.5 Lime

Lime material shall be ground or pulverized limestone


that contains at least 50% total oxides (i.e., calcium oxide plus magnesium oxide). Limestone shall be ground to a fineness such that at least 50% will pass through a 100-mesh sieve and 98 to 100% will pass through a 20-mesh sieve. Granular or pelletized lime may be used, but it must follow the same specifications as above prior to being granulated or pelletized. Applications shall be determined by soil test recommendations.

3.0 Soil Preparation3.1 Subgrade Soil Preparation

A. General conditions: Work shall proceed only after rough grading has been completed and the subgrade is within 2/10 of 1’ (i.e., 2.4") from final subgrade. If the graded area develops volunteer weed growth, the growth must be eliminated at the expense of the general contractor or the owner.

B. Grades: Grades that have been previously established in conformance with the drawings and/or other applicable specifications shall be maintained in a true and even grade.

C. Liming: Limestone shall be spread based on soil test recommendations. Lime shall be distributed uniformly over designated areas and worked into the soil in conjunction with an expanded tillage operation, as described below.

D. Tilling (Scarifying): After the areas have been brought to grade, the subgrade shall be loosened by disking or scarifying to a depth of 2" to 4". This is especially critical when topsoil is to be added.

3.2 Final Grade Soil Preparation With Compost

This specification applies only when compost is used to amend existing subsoil to make it suitable for sod or for sowing seed. The use of compost shall be noted in the contract agreement.

A. General conditions: The areas to which these specifications apply shall be clearly indicated on the drawings or as otherwise specified. The landscape contractor shall furnish equipment, labor, and materials necessary for preparing the specified areas. Work shall proceed only after the subgrade is within 1" of final grade.

B. Grades: Grades in the specified area shall conform to the drawings and/or other applicable specifications and shall be maintained true and even.

C. Applying compost: The compost shall be uniformly applied at a level not to exceed 4 cubic yards per 1000 square feet, 1" thick layer. This level of application

will provide adequate nutrients to supply the needs of the plants through the first growing seasons.

D. Tilling: As soon as the compost has been applied, it shall be incorporated into the top 4" to 6" of soil by either roto-tilling or cross disking.

3.3 Final Grade Preparation With Topsoil

A. General conditions: The areas to which these specifications apply shall be clearly indicated on the drawings or as otherwise specified. The landscape contractor shall furnish equipment, labor, and materials necessary for preparing the specified areas. Work shall proceed upon acceptance of the subgrade by the landscape architect or the owner.

B. Grades: Grades in the specified area shall conform to the drawings and/or other applicable specifications and shall be maintained true and even.

C. Materials: Topsoil shall be as stated above in section 2.3 Topsoil. Topsoil on the existing site may be used but must meet standards.

D. Topsoil installation: Topsoil shall be uniformly distributed on the designated areas to meet final grades. Spreading shall be performed in such a manner that sodding or seeding can proceed with a minimum of additional soil preparation and tillage. Any irregularities in the surface resulting from topsoiling or other operations shall be corrected in order to prevent the formation of depressions or water pockets. Topsoil shall not be placed while in a frozen or muddy condition, when the subgrade is excessively wet, or in a condition that may otherwise be detrimental to proper grading or proposed sodding or seeding.

E. Fertilizer: Fertilizer application rates shall be determined by topsoil test recommendations.

F. Liming: Liming shall be based on topsoil test recommendations.

G. Tilling: If 3" or less of topsoil is added to the site, it must be incorporated into the subgrade by tilling. All amendments must be incorporated to at least a 3" depth.

3.4 Finish Grade

A. General conditions: The landscape contractor shall proceed only after the topsoil or subsoil has been prepared uniformly in the designated areas to within 1/4 of 1". Any undulations or irregularities in the surface resulting from fertilizing, liming, tilling, or other causes shall be leveled prior to sodding or seeding.


B. Prior to sodding or seeding, the surface shall be cleared of all trash, debris, and stones larger than 11/2" in diameter or length, and of all roots, brush, wire, grade stakes and other objects that would interfere with sodding or seeding.

4.0 Sod: Products and Procedures4.1 Scope of Work

The landscape contractor shall furnish all labor, material, and equipment required to complete the work described herein in strict accordance with the drawings and/or terms of the contract. All previously established grades shall be in conformance with the drawings and/or other specifications.

4.2 Products

A. Classes of MD/VA turfgrass sod

1. State certified sod (labeled)

Certified turfgrass sod is a superior product grown from an approved mixture of certified seed. The mixture is made up of individual varieties that have been evaluated for at least five years at up to eight different locations throughout Maryland and Virginia and are readily available in certified form. The mixture is evaluated, mixed, tagged and sealed under the supervision of the Maryland or Virginia Department of Agriculture. The mixture is planted in fields that have been inspected by the Maryland or Virginia Department of Agriculture and declared free of all noxious weeds prior to any plowing or tillage operations by the Department of Agriculture. The fields are periodically inspected throughout the year to ensure: genetic purity; uniformity in density, color and texture; pleasing appearance; free from all noxious weeds and other crop and weed contaminants; proper mowing height; satisfactory root development; relatively disease, insect, and nematode-free; and numerous other requirements for certification. Once the fields are brought to the desired conditions, the Department of Agriculture issues certification labels that must be permanently attached to each bill of lading or delivery ticket. One label is required by law on each and every load of sod, regardless of size. The purchaser should require a “certified” label upon delivery.

2. State-approved sod (labeled)

“Approved” turfgrass sod follows the exact same procedure as above, except that it may have one

controllable broadleaf weed per 1,000 square feet, the color may be slightly off, or the insect and disease levels may be slightly higher than those allowed for certified sod. The sod must meet published state standards and bear an official Maryland or Virginia “Approved Sod” label on the delivery receipt. The purchaser should require such labels when sod is delivered.

3. Other sod

Turfgrass sod that meets and exceeds the standards of state certified and state approved sod and is approved by the owner or owner’s representative.

B. Specifications for sod materials

1. Class and composition: Class of turfgrass sod shall be creeping bentgrass, Kentucky bluegrass, turf-type tall fescue, Bermuda grass, or Zoysiagrass.

2. Thickness of cut: Sod shall be machine cut at a uniform soil thickness of 1/2", plus or minus 1/4", at the time of cutting. Measurement for thickness shall exclude top growth and thatch.

3. Pad size: Individual pieces of sod shall be cut to the supplier’s standard width and length. Maximum allowable deviation from standard widths and lengths shall be 5%. Broken pads and torn or uneven ends will not be acceptable.

4. Strength of sod sections: Under ideal conditions, standard size sections of sod shall be strong enough to support their own weight and retain their size and shape when suspended vertically from a firm grasp on the upper 10% of the section. NOTE: Younger tall fescue will not be strong enough to pass this test but is still okay to use.

5. Sod viability: Sod shall not be harvested or transplanted under drought conditions.

6. Time limitations: Under optimal conditions, sod shall be harvested, delivered and installed within a period of 36 hours. Because sod is a perishable commodity, however, if high temperatures and low moisture extremes occur, its viability declines and installation should occur within 24 hours from harvest. Sod not transplanted within this period shall be inspected and approved or rejected by the owner, owner’s representative, or general contractor prior to installation.

4.3 Installation Procedures for Sod

A. Site approval: The landscape contractor shall inspect


the site to approve final grading and preparation prior to installing the sod.

B. Moistening the soil: During periods of high temperature, lightly irrigate the soil immediately prior to laying the sod.

C. Starter strip: The first row of sod shall be laid in a straight line, with subsequent rows placed parallel to and tightly against each other. Lateral joints shall be staggered to promote more uniform growth and strength. Care shall be exercised to ensure that the sod is not stretched or overlapped and that all joints are butted tightly in order to prevent voids, which would cause air-drying of the roots.

D. Sloping terrain: On sloping terrain where erosion may be a problem, sod should be installed perpendicular to the slope when possible, with staggered joints and secured by sod staples driven to ground level. If staples remain above ground level during sod establishment, either remove or drive to ground level once sod is rooted.

E. Watering and rolling: The landscape contractor shall lightly water sod during installation to prevent excessive drying. As sodding is completed in any one section, the entire area shall be rolled. It shall then be thoroughly irrigated so that the underside of the new sod pad and soil immediately below the sod are thoroughly wet. The general contractor shall be responsible for having adequate water available at the site prior to and during sod installation, unless otherwise stated.

4.4 Acceptance

Acceptance of the installed sod shall be made by the general contractor, landscape architect, or owner within 24 hours of completion of an area or section. After acceptance, the owner is responsible for follow-up maintenance.

4.5 Maintenance

A. Upon acceptance, maintenance becomes the responsibility of the owner unless otherwise specified in the contract.

B. Watering

1. First week: Sod shall be kept moist at all times. In the absence of adequate rainfall, watering shall be performed daily or as often as necessary and in sufficient quantities to maintain moist soil to a depth of at least 2".

2. Second and subsequent weeks: Water the sod as required maintaining adequate moisture in the

upper 4" of soil to promote deep root growth. Once sod is well rooted, less frequent, deep watering should be maintained to encourage deep root growth. The total should equal the equivalent of at least 1" of water per week. This can be accomplished through a combination of rainfall and irrigation.

C. Mowing

1. The first mowing shall be as soon as top growth warrants it. No more than 1/3 of the grass leaf shall be removed by the initial cutting or subsequent cuttings.

2. Grass height shall be maintained at 2" to 3" for Kentucky bluegrass and 21/2" to 31/2" for tall fescue.

4.6 Disclaimer

The landscape contractor shall not be held liable for damages incurred to sod caused by deicing compounds, fertilizer, pesticides, other unauthorized chemical applications, vandalism, and/or acts of God.

4.7 Guarantee

The landscape contractor shall guarantee that all installed sod shall be Maryland/Virginia certified or approved sod, or sod that exceeds the standards for state certified and state approved sod, as approved by the owner or owner’s representative. All sod shall be uniform in color and reasonably free of visible imperfections at acceptance. The landscape contractor shall guarantee the establishment of the sod, only if adequate watering by the contractor has been approved by the owner.

5.0 Seeding: Products and Procedures

5.1 Scope of Work

The landscape contractor shall furnish all labor, material, and equipment required to complete the work described herein in strict accordance with the drawings and/or terms of the contract. All previously established grades shall be in conformance with the drawings and/or other specifications.

5.2 Related Work

1.3 Soil Testing

3.0 Soil Preparation

5.3 Products


A. Mulching materials

1. Straw shall be free of rot, mildew, and noxious weed seeds and shall be a small grain, such as wheat, barley, or oats.

2. Wood cellulose fiber mulch shall consist of specially prepared cellulose processed into a uniform fibrous physical state. The fiber mulch, including dye, shall contain no germination or growth-inhibiting factors. The mulch material shall be manufactured and processed in such a manner that the cellulose fiber mulch will remain in uniform suspension in water under agitation and will blend with seed, fertilizer, and other additives to form a homogeneous slurry. The mulch shall cover and hold grass seed in contact with the soil without inhibiting the growth of the grass seedlings.

3. Wood fiber hydraulic mulch products shall consist of specially prepared wood that has been processed to a uniform fibrous state, and shall be packaged for sale as a hydraulic mulch for use with hydraulic seeding equipment. The wood fibers of wood fiber hydraulic mulch products shall have a length of approximately 0.5" and a diameter of approximately 0.0625". The wood fibers shall be dyed green, or the wood fiber hydraulic mulch product shall be mixed with a dye in a separate operation that will provide appropriate color to aid visual inspection of the material when it is spread. Wood fiber hydraulic mulch products shall have a pH range of pH 4.0 to 8.5, and an ash content that shall not exceed 7% of the product by weight. It shall contain no materials or chemicals in concentrations that inhibit the germination or growth of grasses, forbs, meadow flowers, or other seedlings when they are applied according to the manufacturer’s label directions. It shall be capable of remaining in suspension with water under agitation, so that such products shall readily blend with seed, fertilizer, and limestone to form a uniform slurry.

4. Erosion control blankets shall be woven and may contain lightweight plastic netting on one or both sides.

B. Stabilizing materials

1. A mulch-anchoring tool is a tractor-drawn implement designed to punch and anchor mulch into the soil surface a minimum of 2".

2. Cellulose fiber may be used for anchoring straw. The fiber binding shall be applied at a net dry weight of 750 pounds per acre. The cellulose

fiber may be mixed with water. The mixture shall contain a maximum of 50 pounds of cellulose fiber per 100 gallons of water, or refer to manufacturer’s recommended rates.

3. Wood fiber hydraulic mulch products shall consist of specially prepared wood that has been processed to a uniform fibrous state. The wood fibers of wood fiber hydraulic mulch products shall have a length of approximately 0.5" and a diameter of approximately 0.0625". It shall contain no materials or chemicals in concentrations that inhibit the germination or growth of grasses, forbs, meadow flowers, or other seedlings when they are applied according to the manufacturer’s label directions. It shall be capable of remaining in suspension with water under agitation so that such products shall readily blend with seed, fertilizer, and limestone to form a uniform slurry.

4. Liquid mulch binders should be applied more heavily at the edges, where wind catches the mulch.

5. Lightweight plastic netting should be staked over the mulch according to manufacturer’s recommendations. It is recommended that stakes be driven to ground level or removed once seed is established.

C. Seed mix. Prior to specifying the composition of the certified seed mix or blend and application rates, contact the University of Maryland Extension or refer to www.ipmnet.umd.edu.

5.4 Installation Procedures for Seed

One of the two following methods shall be used for seeding after final soil preparation has been completed. The regular seeding seasons are March 1 to May 15 and August 15 to October 15. Establishment is not guaranteed when the seeding is done out of season. No seeding shall be done on frozen ground or when the temperature is 32° F or lower. Optimum seeding time is late August to mid October.

A. Dry application

• Seed installationa. Cultipacker seeder: This method applies seed

just below soil surface and covers the seed in a single operation. Seed should be applied within the top 1/4" of the soil in two different directions for best results.

b. Drop-type/broadcast spreader: Apply seed within the top 1/4" of the soil in two


directions for best results. To improve soil/seed contact, use a landscape rake to make one pass over the seed bed.

1. Mulching: Apply mulching material to retain moisture and minimize erosion. Rate for straw: 1/2" to 1" thick layer or 60 to 80 bales per acre. Rate for cellulose fiber: 1,500 pounds per acre.

2. Stabilizing: Stabilize the mulch by using a mulch anchoring tool, cellulose fiber, liquid mulch binders, or mulch netting.

B. Hydro-seeding: Two methods can be used. The first method gives the best results.

1. Water, seed, and fertilizer method: The mixture shall be sprayed on the previously prepared seedbed in the form of an aqueous mixture. All mixtures shall be constantly agitated from the time they are mixed until they are finally applied to the seedbed.

If the fertilizer is mixed into the slurry, no more than 30 minutes should lapse before it is applied to prevent the fertilizer from burning the seed. Care shall be exercised to ensure uniform coverage.

Straw shall be applied by hand or with a straw blower and stabilized. The same rates and procedures shall be followed as detailed for dry application above.

2. Seed, fertilizer, water, and cellulose fiber method: The application procedure for this method is the same as for the first method above. The rate of cellulose fiber is 50 pounds per 100 gallons of water. Follow manufacturer’s recommended rates.

5.5 Cleanup

Excess and waste material shall be removed daily. All pavements shall be left broom cleaned, and all damaged areas in existing turf shall be restored to their original condition. Responsibilities should be based on contractual agreements.

5.6 Acceptance

Acceptance of the seed installation shall be made by the general contractor, landscape architect, or owner upon completion of an area or section. After acceptance, the owner is responsible for follow-up maintenance.

5.7 Maintenance

A. Upon acceptance, maintenance becomes the responsibility of the owner, unless otherwise specified in the contract.

B. Watering: During the first two to three weeks, the seed shall be kept moist at all times to allow for germination. In the absence of adequate rainfall, light, frequent watering shall be performed to keep the seedbed moist.

5.8 Guarantee

The landscape contractor shall guarantee germination for seed installed during the regular season, provided that watering is performed by the owner.

5.9 Disclaimer

The landscape contractor shall not be held liable for damages incurred to seed caused by deicing compounds, fertilizer, pesticides, other unauthorized chemical applications, vandalism and/or acts of God. Any need for overseeding or regrading attributed to this shall be an addition to the contract.

6.0 Crown VetchPlease refer to the Maryland Seeding Association Guideline Specifications for information about procedures for using Crown Vetch at www.marylandseeding.org.

6th edition


Soils

Landscape Specification Guidelines 1 Soils

1.0 General Conditions1.1 Site Analysis

A. Prior to developing recommendations for soil modifications, an analysis of existing soil conditions shall be made. All information shall be recorded on a scale drawing of the site. The soil section of the specification guidelines is dependent on the site analysis being completed prior to determining recommendations for soil modifications. It is the responsibility of the landscape contractor to perform the analysis, unless the owner provides soil modifications in the bid package. If the owner refers to the specification guidelines and makes specific soil modification recommendations, the landscape contractor can assume that the owner has undertaken this analysis prior to preparing the bid documents. It is necessary to comply with all local codes regarding disturbance and sediment control requirements.

B. The analysis shall include the following:

1. Analysis of historical land use to determine previous development activity and soil disturbance at the site. The historical land use analysis shall include consideration of construction activity at the site that will occur between the time of the analysis and the time of the installation of new plantings.

2. Analysis of existing vegetative cover and topography that may indicate variability in soil conditions.

3. Sampling of existing soils, as follows:

a. Identify areas with different soil conditions based on historical, topographic, and vegetative analysis.

b. For each area, take a minimum of one composite soil sample (1 cup) that consists of five (5) core samples. Each core sample shall be taken at a depth of 6–8" after first removing the upper duff layer, if any. The five (5) core samples are to be mixed and air- dried prior to submittal to the testing laboratory.

c. Soil testing shall be as per section 1.7 Soil Testing.

d. If the soil in the top 6–8" of soil indicates a pH level two or more units above or below the optimum pH level desired, additional testing of subsoil pH is recommended.

e. A second sample at a depth of 18-24 inches is advisable to test for subsurface soil conditions

and is to be mixed and air-dried prior to submittal to the testing laboratory. Do NOT mix upper layer and lower layer soil samples; they need to be tested separately.

4. Compaction analysis

a. Based on historical, vegetative, and topographic analysis, determine areas of the sites that may have been compacted. For any area of the site where compaction potential has been identified, perform multiple soil penetrometer tests to determine degree and extent of compaction.

b. Conduct a penetration resistance test as follows:

Penetration reading must be taken when soil moisture is at field capacity (several days after free drainage). Using a cone penetrometer), apply slow, even pressure so that the penetrometer advances in the soil at a rate of 4 seconds per 6". Record pressure readings at 0–4" depth (surface soil) and at 10–14" depth (subsoil).

Pressure in psi shall be as follows:

<110 psi surface soil (all textures);

<260 psi subsurface soil – loamy sand, sandy loam, sandy clay loam, sandy clay, loam, silt loam, silty clay loam, and silty clay;

<225 psi subsurface soil – clay loam

c. A bulk density test shall be performed if the results of the penetrometer are outside the acceptable range. The contractor is to notify owner if this is needed.

5. Drainage analysis:

a. Determine areas that are suspected to be poorly drained based on the site analysis and the topography.

b. Soils that exhibit the following characteristics shall be considered poorly drained:

Standing waterAnaerobic soils (may have objectionable odor)Gray soils (hydric)Presence of wetland species

C. Definitions of soils and planting mixes are as follows:

1. Existing soils are soils that are present on the site at the time of estimating.


2. Imported soils are soils that are brought onto the site during the course of the job. Onsite stockpiles of soil that may have been present at the time of estimating shall also be considered imported soils.

3. Planting soils are the prepared and often amended soils, whether they are existing, imported, or a blend of both existing and imported soils, that will be at the surface of the soil profile when planting begins. The goal of this specification is to help create excellent planting soils that more effectively support healthy plant growth.

4. Planting mixes are blends of soils; sand/soil/compost; and soil-less media used to grow plants. A typical use of planting mixes is to fill planters located above structure.

5. Subsoil is soil that, in an undisturbed soil profile, would be the B horizon. In many cases, developers have removed the A or C horizon from the site, so the surface soil is actually a subsoil.

D. Based on the above analysis and definitions, prepare a composite drawing identifying the soil characteristics based on the following categories.

1. Minimum soil modification required to create planting soils, as follows:a. Nutrient and pH adjustments less than 0.5

pH units, in either direction on the pH scale, to existing soils. The range is based on the pH tolerance of the plants being placed in that location.

b. Addition of organic amendments to the existing soils.

c. Tilling of existing soils.

2. Significant modification(s) required to create planting soils, as follows: (in addition to the requirements of paragraph D.1)a. Subsoiling to reduce compaction below

planting soils.b. Installing subsurface drainage.c. Regrading to improve surface drainage.d. Significant pH adjustment to existing soil or

subsoil of more than 0.5 pH units.e. Adding imported soils or planting mixes.

3. Significant modifications beyond the scope of these specifications. The following conditions require consultation with a soil specialist to determine appropriate action:a. Soils containing quantities of man-made

inerts, such as drywall material (Gypsum),

considered harmful to plant growth.b. Soils suspected of containing harmful

chemical contaminants.c. Soils suspected of containing naturally

occurring compounds harmful to plant growth that are not easily mediated.

d. Subsoil conditions that require modifications beyond basic drainage and subsoiling.

e. Soils not classified as a type of loam (e.g., clay, clay/silt, sand, sandy clay) using the USDA soils classification.

1.2 Scope of Work

A. The landscape contractor shall provide all materials, labor, and equipment to complete all soil and/or drainage work as shown on the plans and specifications.

B. All soils and drainage work within the critical root zone of any tree to remain shall be undertaken in such a manner so as to comply with the tree preservation requirements specified in the Tree Preservation Section.

1.3 Submittals

When requested by the owner, samples of all soil, planting mix, and drainage materials shall be submitted to the owner or owner’s designated representative for approval. For soil, planting mix, and organic amendments, submit 1-pound samples and the required soil testing results. For other materials, submit the manufacturer’s product literature.

1.4 Approvals


1.5 Utilities and Underground Features

A. The landscape contractor shall notify utility companies and/or the general contractor in advance of construction to locate the utilities. Please contact Miss Utility at www.missutility.net for Maryland, D.C., Virginia, and Delaware.

B. Private underground features, such as irrigation systems, septic systems, drain systems, invisible pet fencing, landscape lighting, underground natural gas, and security systems, shall be located by the owner or general contractor.

C. If there is a conflict with the utilities and the proposed soil work, the owner shall be responsible for changing the design requirements. Any costs incurred for changing soil design requirements shall be borne by the owner.



The correction of undisclosed subsurface conditions, such as rocks, roots, stumps, poor drainage, water, clay pan, soils contaminated with toxic substances, or other obstacles encountered in excavation work that are not apparent at the time of estimating or indicated on the soil analysis, may result in additional costs to the owner. Upon discovery of undisclosed conditions, the landscape contractor shall notify the owner of any items to be corrected and the associated costs, if any, before corrective measures are taken. Notification, change orders, and approval shall be in writing.

1.7 Soil Testing

A. Soil tests shall be made of existing soils, imported soils, and planting mixes to determine soil texture, pH, total calcium, magnesium, phosphorous, potassium, soluble salts and percent organic matter. Each sample to be submitted for testing shall be extracted from a composite sample representing a minimum five (5) core samples for each soil area. Soil tests shall be conducted by a state agricultural soil testing laboratory or by a commercial agricultural soil testing laboratory.

B. All soil testing costs shall be borne by the landscape contractor. If the owner has already tested the existing soil prior to the preparation of bid documents, the soil test results shall be provided to the landscape contractor so that they may be included in the composite soil analysis plan.

C. Each soil test shall examine the following chemical and physical attributes. Any soil that falls within the indicated range of results shall be considered provisionally acceptable. Soil that falls outside of any of the indicated ranges may be amended, retested, and resubmitted for approval by the owner. Once a soil is considered provisionally acceptable, its pH level should be examined for suitability with the plants that are to be grown on the site. Special attention should be paid to the pH tolerances of plants that require acidic soil for healthy growth.

The following nutrient recommendations are for turf but may include a variety of landscape plants. Recommended nutrient ranges vary widely, and depending on soil characteristics and laboratory nutrient extraction methods, test results can also vary greatly. Nutrient availability is soil pH dependent. Some nutrients, like iron, zinc and, manganese, are minimally available in high pH soils and are very available in acidic soils.

Plant requirements for pH vary. Most plants do well in a pH between 6.0 and 6.8, where most nutrients

are optimally available. However, some species, like ericaceous plants (e.g., Rhododendron, Azaleas, Pieris), require low pH soils, whereas others (e.g., Cercis sp.) may require higher pH soils. Avoid placing plants with different pH soil requirements together.

Suggested Ranges

Nutrient Parts per Million ConcentrationDepending on CEC*

Calcium 400 to 4,000

Magnesium 60 to 450

Potassium 91 to 250

Phosphorus 30 to 50

If the following nutrients are analyzed (suggested for sandy soils)

Iron 5 to 20

Manganese 5 to 20

Copper 0.3 to 1

Boron 0.5 to 1

Zinc 1 to 3

**SS 0.2 to 1/5 mmhos/cm

pH 6.0 to 7.5

*Ca, K ,and Mg optimal ranges depend on the ability of a soil to hold cations

(Cation Exchange Capacity). Nutrient levels shall be as recommended by the soils lab for the types of plants and soil conditions.

**Soluble salts or electrical conductivity (EC) depend on the type of test being performed. The recommendation is for a 1:1 soil/water extract. The EC units of mmhos/cm, dS/m, and mS/cm are interchangeable.

D. These additional tests are required when the following conditions exist:

Condition Test Required Acceptable Results

sandy soils boron 0.5–2.0 ppm

hardwood forest soils or history of

continuous mulching with hardwood bark

manganese 15–40 ppm

seaside and bay side sodium *

imported soils, planting mixes

mechanical analysis, including particle

size analysis of sand fraction

Requirements vary dependent

on application and may require the

recommendation of a soils expert.

* Soils relatively high in sodium (Na) and low in other base cations (calcium, potassium and magnesium) are considered sodic soils. Proportionally high Na can lead to plant toxicities or nutrient deficiencies. Sodic soils usually have high pH above 8.5. Sodium can start to be a problem if its % Base Saturation is greater than 5%, especially in clay soils. Electrical Conductivity should be below 4 dS/m (mmho/cm) or you may have saline soils (a mixture of many nutrients). Corrective actions to remove Na from soil include application of calcium, usually by calcium sulfate (gypsum). Gypsum should not be used if soil EC is above 4 dS/m (mmho/cm).

E. In the event that pH is higher than the limits of the plants specified, the plant type shall be changed to a plant that is adaptable to the pH of the soil.


F. In the event that the owner rejects the recommendations of the soil test and requires the landscape contractor to proceed with planting in soils that otherwise require amendments, the landscape contractor may void the guarantee for plantings or lawns. In the event that the contractor voids the guarantee, the owner shall be notified in writing of such action prior to the installation of any plantings or lawns. No consideration of changes to the conditions of the guarantee will be allowed without written notification prior to planting.

1.8 Workmanship

A. During the delivery and installation of soils and drainage, the landscape contractor shall perform in a professional manner, coordinating his/her activities so as not to interfere unduly with the work of other trades and leaving his/her work area(s) neat and clean of litter and debris at the close of each workday.

B. Upon completion, all debris and waste material resulting from soil and drainage operations shall be removed from the project and the area cleaned up.

C. Any damaged areas caused by the landscape contractor shall be restored to their original condition.

2.0 Products2.1 Organic Amendments

A. The following is a list of types of organic amendments that may be used as soil amendments.

1. Sedge peat – decomposed peat containing no identifiable fibers.

2. Yard debris mature compost (e.g., Leafgro) – leaves, grass clippings, and prunings screened through a 3/4" screen and containing less than 1% man-made inerts.Compost: Organic blended material, properly composted at temperatures sufficient to break down all woody fibers, seeds, and leaf structures; free of toxic and nonorganic matter. Source material shall be yard waste trimmings blended with other organic material designed to produce compost high in fungal material.Compost shall be commercially prepared compost and meet U.S. Compost Council STA/TMECC criteria, or as modified in this section for stable, mature compost intended for landscape backfill mix component.http://compostingcouncil.org/admin/wp-content/plugins/wp-pdfupload/pdf/191/LandscapeArch_Specs.pdf

Compost shall comply with the following parameters:

a. pH 5.5–8.0

b. Salt concentration (electrical conductivity) maximum 5 dS/m (mmhos/cm).

c. Moisture content %, wet weight basis 30–60%.

d. Particle size % passing a selected mesh size, dry weight basis 98% pass through 3/4" screen or smaller.

e. Solvita maturity test – 6 or higher.

f. Physical contaminants (inerts) %, dry weight basis <1.

g. Chemical contaminants mg/kg (ppm) meet or exceed U.S. EPA Class A standard, 40 CFR § 503.13, Tables 1 and 3 levels.

h. Biological contaminants select pathogens fecal coliform, bacteria, or salmonella, meet or exceed U.S. EPA Class A standard, 40 CFR § 503.32(a) levels.

3. Animal manure mature compost made from poultry, swine, cattle, or equine manures composted with bedding, wood waste, or yard debris.

4. Pine Bark – potting grade pine bark screened through a 3/4" screen and containing less than 10% sapwood fibers. Any pine bark containing more than 10% sapwood must be composted through the first heat stage.

5. Pine Fines – a product derived from the processing and composting of pine bark mulch containing a minimum of 75% sawdust size and dust- sized particles.

2.2 Imported Soils

A. Imported soil shall meet acceptable soil test levels as specified in section 1.7, Soil Testing. A certificate of soil test analysis, soil source location, and list of crops grown in the soil over the past three years must be submitted to the owner for approval before any soil is delivered to the project. Submit a 1-pound sample of soil source of each soil to accompany soil test.

B. Imported soils shall be loams of textural classification specified for each application. Unless otherwise indicated, imported soil installed on grade shall be suitable for the plants to be grown. In extreme clay or sandy subsoil, follow recommendations of a soil specialist.


C. Imported soil shall not contain toxic substances harmful to plant growth. The total volume of stones, green plant parts, fibrous root mats, man-made inert material and wood or woody roots in the soil shall not exceed 5%. Soil shall not contain sharp glass or metal objects. Imported soil shall also be free of Bermuda Grass, Quack Grass, Johnson Grass, Mugwort, Nutsedge, Poison Ivy, Canada Thistle, and other invasive weeds.

D. Imported soil shall not be harvested, transported, and/or graded when soil moisture exceeds field capacity or when the material is frozen.

E. Protect imported soil stockpiles from erosion, saturation, or weed growth using plastic sheeting or tarps.

2.3 Planting Mixes

A. The recommendations of mix requirements is application specific and beyond the scope of this specification guideline. Consult a soil specialist for planting mix specifications.

B. To minimize volume reduction over time, only the following organic sources shall be permitted: milled pine bark, pine fines, mature yard debris compost (e.g., Leafgro) or manure compost.

C. Planting mixes shall be blended mechanically using a commercial mixer or shredder. Ingredients shall be uniformly incorporated to obtain a consistent blend.

D. Protect plant mix stockpiles after mixing by using plastic sheeting or tarps.

E. Prior to mixing any planting mix, prepare sample mix ratios and submit to the owner for approval along with test results. If the sample does not meet the mix criteria, resubmit alternative mix ratio samples with test results.

2.4 Fertilizers

All fertilizers shall be uniform in composition, free flowing, and suitable for application with approved equipment. Fertilizers shall be delivered to the site fully labeled according to applicable state fertilizer laws and shall bear the name, trade name, or trademark and warranty of the producer. Application rates shall be determined by soil test recommendations.

2.5 Lime

Lime material shall be ground or pulverized limestone that contains at least 50% total oxides. The use of either dolomitic lime (lime with magnesium) or calcitic lime (lime without magnesium) shall be determined by soil

test recommendations. Limestone shall be ground to such fineness that at least 50% will pass through a 100-mesh sieve and 98–100% will pass through a 20-mesh sieve. Granular or pelletized lime may be used but it must follow the same specifications as above prior to being granulated or pelletized.

2.6 Acidifying Amendment

Acidifying amendments shall be flowers of sulfur, pelletized sulfur, granular sulfur, or iron sulfate. The application rates of these materials will be determined by soil test recommendations.

2.7 Subsurface Drain Lines

Subsurface drain lines shall be perforated, corrugated polyethylene plastic drainpipe with manufacturers’ standard connectors such as tee’s, elbows, caps.

2.8 Gravel

Gravel shall be pea gravel or AASHTO #57 crushed stone.

2.9 Filter Fabric

Non-woven, continuous filament polyester fabric with a weight of 4.0 oz. per square yard, minimum grab strength of 100 lb., and a water flow rate of 100 gpm per minute.

2.10 Coarse Sand

Coarse concrete sand, ASTM C-33 Fine Aggregate.

3.0 Soil Preparation3.1 Minimum Modifications to Create Planting Soils

A. General conditions

1. Identify utilities and underground utilities (see section 1.5). All areas on either side of the utility marking, where the distance is dictated by the local jurisdiction, shall be amended by hand.

2. Prior to amending soils, the general contractor or owner shall clear the surface of all trash, debris and stones larger than 11/2" in diameter or length, and of all roots, brush, weeds, grass, wire, grade stakes and other objects that would interfere with soil preparation. Installation of all utilities and irrigation mainlines shall be completed prior to beginning soil work.

3. The soil shall not be tilled or amended when the soil’s moisture level is above field capacity or when the soil is frozen.


4. Grades after amendment, tilling, and fine grading in the specified area shall conform to the drawings and/or other applicable specifications and shall be maintained true and even.

5. Rototilling shall not be performed within the critical root zone of existing trees.

3.2 Modifications to Existing Soils


1. Amendments shall be applied uniformly based on the following recommendations and soil test results. Thoroughly incorporate the amendments into the upper 6" of soil. After adding amendments, retest planting soil to confirm that the soil has responded to meet the design criteria. Submit the test results to the owner for approval.

a. Soils with optimum nutrient concentration but with excessively high pH levels shall be amended with pine bark or pine fines and acidifying amendments to lower pH to desired level. Soils with adequate levels of nutrients and organic matter shall be amended with lime or acidifying agents (if necessary) depending on the pH requirements of plants. The contractor may also suggest changing the plant(s) to those that meet the existing pH conditions.

b. Soils with an acceptable pH but low levels of potassium or low organic matter shall be amended with yard debris compost or animal manure compost.

c. Soils with an acceptable pH and with adequate amounts of organic matter but low in nutrients shall be amended with fertilizers based on the soil test results.

d. To reduce the bulk density of clay loam soils, in the upper 6" of soil, amend with pine fines or compost. For example, on a typical landscape clay loam soil, place a 2" layer of compost and till to a 6" depth.

e. To reduce bulk density deeper than 6", subsoil using a back hoe bucket or ripping bar to the depth of the compaction or to a minimum of 30" depth. Then add compost to the surface and till the soil using a rototiller to a depth of 6".

3.3 Significant Modifications to Create Planting Soils


1. Identify utilities and underground utilities (see section 1.5). All areas on either side of the utility

marking, where the distance is dictated by the local jurisdiction, shall be amended by hand.

2. Prior to amending soils, the general contractor or owner shall clear the surface of all trash, debris, and stones larger than 11/2" in diameter or length, and of all roots, brush, weeds, grass, wire, grade stakes, and other objects that would interfere with soil preparation. Installation of all utilities and irrigation mainlines shall be completed prior to beginning soil work.

3. The soil shall not be tilled, re-graded, amended, or otherwise worked when the soil’s moisture level is above field capacity or when the soil is frozen.

4. Grades after amendment, tilling, and fine grading in the specified area shall conform to the drawings and/or other applicable specifications and shall be maintained true and even.

5. Work to add soil shall proceed only after rough grading of the subsoil has been completed and the subgrade is within 1" to 2" from final subgrade, as indicated on the drawings. If the rough-graded area develops volunteer weed growth, the growth must be eliminated prior to spreading the imported soil at the expense of the general contractor or owner.

6. Rototilling shall not be performed within the critical root zone of existing trees.

3.4 Subsoiling to Reduce Compaction

A. Subsoiling shall be done using a trencher (e.g., Ditchwitch), backhoe, mini- excavator, or rotary spader. Do not use a vibratory plow. Subsoiling may be performed when soil is neither wet nor dry. If a shovel cannot be forced into the soil, it is too dry. If the surface is sticky or muddy, it is too wet.

B. The subsoiler shall penetrate the soil to a depth of 24" at a maximum 24" interval with two passes in each area at 90 degrees to each other. In sloped areas, the first pass of subsoiling equipment shall be across the slope. The second pass of subsoiling equipment shall be up and down the slope.

C. If the soil being subsoiled is a loam, silt loam, or clay loam, spread a 4" to 6" layer of pine fines, pine bark, or mature compost.

D. Use a backhoe rear bucket or similar equipment with a tined bucket to break up the compacted soil and incorporate the compost. Work backwards away from excavated soils so that treated soil is not trafficked by the equipment. Insert the bucket


through the compost layer and into the subsoil to a depth of 24" and raise a bucket of soil at least 24" above the soil surface. Tip the bucket and allow soil to fall. Repeat this procedure until no clumps of compacted soil larger than 12" in diameter remain. The tines of the bucket can be used to break apart larger clumps if necessary. 50% of the soil shall be in clumps 6" or smaller. No clumps shall be greater than 18" in diameter. The subsoiling is not intended to homogenize the compost and soil, but rather loosen the soil to a 24"depth and create veins of compost down to that depth as well. To ensure that subsoiling reached the appropriate depth, a push tube soil sampler shall be used to verify that compost is present at 24" depth.

3.5 Installing Subsurface Drainage

A. All subsurface drainage work should be completed as indicated on the drawing or as described in the contract. The plan shall identify the location of all drain lines, the desired slope of the drain lines and the depth they will be set, the materials and details to be used, and any required connections. The recommendations of the plan should be provided by the landscape contractor, preferably with the advice of a soils expert, or from drawings provided by the owner or owner’s representative.

1. Absent a plan developed prior to bidding, the following minimum standards shall apply to any area where subsurface drain lines are requested by the owner or required by field conditions.

a. Provide one drain line at the lowest portion of each turf or planting soil area that is aligned parallel to any walk, property line or structure that defines the edge of the planting soil bed.

b. Provide additional lines at a minimum of 20 feet on center throughout the turf or planting soil area. The alignment of the lines shall be such that they flow at a minimum slope of 1% when set approximately parallel to the final grade contours.

c. All lines shall be terminated in a location that allows the water to flow onto the surface or be connected to a storm drain where available.

B. Provide horizontal field engineering at all times when drain lines are being installed to ensure that the slope on all perforated drain lines is positive toward itsintended outfall and also remains at the correct depth as shown on the drawings.

C. Excavate a trench a minimum of 8" wide to a depth required to provide positive drainage from the high

points of the system to the outfall or connection point to a storm sewer. Eliminate dips or rises that will trap water. The invert of the pipe shall be a minimum of 4" below the depth of the top of the subgrade soil.

D. Install the drain lines using one of the following two options.

1. Sand filter option (preferred): Install the drain lines in a bed of coarse sand. Provide a minimum of 2" of coarse sand on the bottom and sides of the drain line and a minimum of 4" on top and sides of the pipe. Place the pipe with the perforations facing toward the bottom of the trench. In the case where pipe is used that has perforations on all sides of the pipe, place a 10" wide strip of 4 ml plastic over the top and sides of the pipes before adding sand to the sides and top of the trench.

2. Gravel/filter cloth option: Install the drainage gravel to the depths and profiles shown on the drawings. Provide a minimum of 2" of gravel on the bottom and sides of the drain line and a minimum of 4" on top of the pipe. Wrap the gravel in filter fabric according to the drainage details. Provide a minimum of 8’ of overlap where the filter cloth comes together. Phase the construction to keep the gravel from being contaminated with soil.

E. All connections and splices shall use the pipe manufacturer’s standard fittings. All joints shall be secure.

F. When the top of the sand or filter cloth is below depth of the planting soil or bed preparation, backfill the trench with coarse sand or gravel to the elevation of the top of the subgrade soil.

3.6 Adding Soils or Planting Mixes

A. Add imported soil or planting mix when required on the drawings. The limits and depths of the soil to be added shall be as indicated on the drawings. Depths shall be as measured from the top of the subsoil to the fine graded soil level for mulched and seeded lawn areas and to the bottom of the sod for sodded lawn areas. All soil depths are to be as measured after initial compaction and 12 months settlement.

B. All subsoil modification, installation of drain lines, planter drainage and rough grading shall be completed prior to adding soils. All subgrades shall be inspected by the owner or owner’s representative and approved prior to adding soils.

C. Till the subgrade to a minimum depth of 6" or


scarify to a depth of 4 inches using the teeth of a back hoe just prior to adding the first lift of soil or planting mix. This is in addition to any other required subsoiling. Leave the subgrade rough to receive imported soils and break soil interface lines. Tilling may be accomplished with a rototiller, the teeth of a backhoe bucket, an agricultural plow, or other suitable equipment.

D. Add imported soil or planting mix in lifts not to exceed 12" in depth.

1. Compact each soil lift using a plate vibrator or light roller to a density between 100 and 250 psi reading with a penetrometer.

2. Soil that has been compacted should drain water at the rate of 1" per hour. Soils that drain less than 1" per hour are considered over-compacted and must be tilled and rolled again.

3.7 Significant pH Adjustment of Planting Soils and/or Subsoils

A. If the pH of the subsoil is more than 0.5 pH units above or below the desired range, amend with the recommended amount of lime or acidifying amendment and incorporate into the upper 4" to 6" of the subsoil prior to establishing the subgrade. If the subsoil is more than 2 pH units above the desired range, till a 2" layer of pine fines into the top 6" of the sub-grade soil.

B. If the pH of the existing soils is more than 2 pH units above or below the desired range, amend with the recommended amount of lime or acidifying amendment and incorporate into the upper 4" to 6" of the existing soil prior to fine grading. If the existing soil has a pH that is more than 2 units above the desired range, incorporate a 2" layer of pine fines in addition to the acidifying amendment.

3.8 Grading

A. All grading to improve surface drainage shall be done according to an agreed- upon plan. The plan shall identify the location, slope, and details of any areas that are to be graded or swales to be created. The recommendations of the plan should be provided by the landscape contractor or from drawings provided by the owner or owner’s representative.

B. Provide horizontal field engineering to ensure appropriate slopes of the swales and final grades.

C. Avoid unnecessary compaction of the soil during grading.

3.9 Soil Compaction Testing

A. Following grading or soil installation, test the soil compaction with the penetrometer.

B. Prior to testing the soil with the penetrometer, check the soil moisture. Penetrometer readings are impacted by soil moisture, and excessively wet or dry soils will read significantly lower or higher than soils at optimum moisture.

C. The penetrometer readings shall be within 100–250 psi to the full depth of the installed soil or to a depth of the amended or tilled soil, whichever is greater, when moisture levels are consistent with soil moisture during time of installation.

D. Any areas that fail to meet the above criteria shall, if requested by the owner, be reworked to attain the required compaction.

E. Make the penetrometer available to the owner for use in observing the soil compaction. The owner may at any time check the compaction in the soil.

3.10 Cleanup

A. Immediately following each day’s work, clean all dirt, excess soil, debris, and trash from the job site. Store additional soils in stockpiles protected from erosion and contamination by other contractors with tarps.

B. At the end of the installation of all soils, leave the site in a clean and clear condition. Dispose of all dirt, excess soil, debris, and trash in a legal manner off site.

3.11 Protection

A. Maintain grades and protect soil from erosion, compaction and contamination until planting/seeding/sodding operations begin.

B. Restore any erosion washes, break compaction by tilling, and remove and replace any contaminated soils.

3.12 Restoring Settled Grades

Soil that settles below the design grade as a result of work completed by the landscape contractor shall be re-graded 12 months after completion by removing the mulch or sod and adding additional soil. Soil that settles as a result of work performed by other trades (examples include, but are not limited to, backfilling of utilities, walls, and foundations and the lack of compaction thereof) shall not be the responsibility of the landscape contractor.

6th edition


Tree Preservation

Landscape Specification Guidelines 1 Tree Preservation

1.0 General ConditionsThe Maryland Forest Conservation Act was passed by the General Assembly in 1991 and was subsequently amended to conserve the state’s forest resources during development activities. The Act requires identification of existing forest stands, protection of the most desirable forest stands, and establishment of areas where new forest can be planted.

The Forest Conservation Act establishes standards for local authorities to enforce during the development process and is a means to protect not only forests and trees in developing areas, but also any sensitive areas identified during the local planning or comprehensive land use plan adoption process.

1.1 Basic Planning Requirements

The Maryland Forest Conservation Act of 1991 requires that prior to the approval of any public or private subdivision, project plan, grading plan permit, or sediment control permit on a unit of land 40,000 square feet or greater, applicants shall submit a Forest Stand Delineation (FSD) and a Forest Conservation Plan (FCP). These plans shall be approved by the local authority under a locally adopted forest conservation program, or the Department of Natural Resources where no local program is in effect, before other approvals are given.

1.2 Forest Stand Delineation

The FSD is an inventory of existing site conditions and forest and shall be used during the preliminary review process to determine the most suitable and practical areas for forest conservation during development. Only qualified professionals approved by the Department of Natural Resources, Forest Service, or, for local applications, an adopted and approved local forest conservation program, may prepare a an FSD Plan.

1.3 Forest Conservation Plan

The FCP details the amount of the forest that will be retained, reforested, or afforested; the locations where this will occur; proposed protection measures taken during development, such as location of devices and limits of disturbance; construction scheduling, maintenance, and monitoring procedures; long-term protection measures; and other measures that may be required. The plan can be divided into five principal topics:

1. Determining Priority Forest and Priority Areas2. Retained Forest and Tree Protection3. Forest and Tree Planting4. Maintenance and Monitoring5. Enforcement

An FCP must be prepared by a Maryland Licensed Forester, Maryland Licensed Landscape Architect, or other qualified professional. A stamp or certification by the preparer shall appear on the submission.

2.0 DefinitionsA. Caliper: The diameter of a tree trunk less than 12"

measured at 4" to 12" above the ground. From 1" to 4" it is measured 6" above the ground, and from 4" to 12" it is measured 12" from the ground.

B. Champion Tree: The largest of its species, as determined by the Maryland Department of Natural Resources.

C. Critical Root Zone: A circular region measured outward from a tree trunk representing the area of the roots that must be maintained or protected for the tree’s survival. Usually it is 1 ft of radial distance for every inch of tree diameter (DBH) measured at 4.5 ft above the ground, with a minimum radius of 8 ft. For specimen trees, the critical root zone shall be 1.5 ft for every inch of tree diameter.

D. Diameter Breast Height: The height at which a tree is measured that is over 12" in diameter. This measurement is taken 4.5 ft above the ground.

E. Landscaping Plan: A plan, drawn to scale, showing dimensions and details for re-vegetating an area 2,500 ft2 or greater in size and at least 35 ft wide, including maintenance and protection measures.

F. Reforestation or Reforested: The creation of a biological community dominated by trees and other woody plants containing at least 100 live trees per acre, with at least 50% of those trees having the potential of attaining a 2" or greater diameter measured at 4.5 ft above the ground, within seven years. Reforestation includes landscaping of areas under an approved landscaping plan that establishes a forest at least 35 ft wide and covering 2,500 ft2 of area. Afforestation is the establishment of a forest in an area on which forest cover has been absent for a long period of time, or the planting of open areas that are not presently in forest cover.

G. Seedlings: An un-branched woody plant, less than 24" in height and having a diameter of less than 1/2" caliper measured at 2" above the root collar.

H. Selective Clearing: The careful and planned removal of trees and plants using specific standards and protective measures under certain conditions, as established in an approved FCP.

I. Specimen Tree: Trees having a diameter of 30" or more measured at 4.5 ft above the ground, or trees


having 75% or more of the diameter of the current State Champion of that species. Also includes Champion trees.

J. Temporary Tree Protection Devices: Structural measures, such as fencing or berms, installed prior to construction for the purpose of preventing access to forest retention areas or afforested or reforested areas during construction.

K. Tree: A large, branched, woody plant having one or several self-supporting stems or trunks that reach a height of at least 20 ft at maturity.

L. Tree Line: The boundaries of existing forests, as determined by the most recent aerial photography and field verification.

M. Understory Trees: Trees with crowns entirely below the general level of the canopy, receiving little or no sunlight from above or the sides.

N. Whip: An un-branched woody plant greater than 24" in height and having a diameter of less than 1" caliper measured at 6" above the root collar.

3.0 Forest and Tree ProtectionThe final FCP map shall locate and describe any protection mechanisms to be installed to protect retention areas during and after construction. These mechanisms shall be field-located and approved by inspection prior to the start of construction.

Any clearing, grading, or construction within 50 ft of the retention area will require protection devices, including, but not limited to, fencing or adapted sediment and erosion control devices and signs, as indicated in the approved FCP. All protection devices shall remain in place until construction completion, final inspection, and issuance of an occupancy permit, unless waived by the approving authority.

3.1 Critical Root Zones

The Critical Root Zone of a tree is the zone in which most of the roots live. Ninety-five percent of the roots of most trees will be found in the upper 12" to 18" of the soil. Most of the roots that supply the nutrients and water to the tree are found just below the soil surface. The total amount of a tree’s roots is generally proportional to the volume of the tree’s canopy. Therefore, if the roots only penetrate a thin layer of soil, then the roots must spread far from the tree, beyond the extension of the canopy. When delineating forest retention lines in the field, consider not only the visible portion of the tree—the trunk and canopy—but also the belowground portion as well.

3.2 Forest or Tree Protection Procedures

Forest or tree protection procedures can be summarized in the following steps.

A. Field-locate the proposed retention boundary as shown on the preliminary FCP.

B. Field-locate the proposed limit of disturbance. If this does not agree with the preliminary approved retention area, revise the FCP map and calculations to show adjusted retention areas, if needed.

C. Evaluate tree conditions and critical root zones.

D. Field-adjust and stake the retention boundary. In general, if more than 30 percent of the critical root zone is to be disturbed, the tree should not be included in the retention area. Some soil disturbance may be mitigated by selective stress reduction pruning or other methods.

E. Obtain final FCP approval, if not obtained earlier. Notify approving authority for inspection approval or installed devices.

F. Proceed with construction, subject to final approvals.

Notify approving authority following completion of construction for final inspection.

4.0 Construction TechniquesThe FCP not only locates the forest retention boundary, but also includes details and specifications for forest protection. As a construction document, it directs construction contractors and others in the correct design, installation, timing, and placement of specific protection devices and protection measures. Strict adherence to the FCP details and specifications will be enforced. If plans have not been prepared, the owner is responsible for contacting a qualified professional to prepare an FCP. All plans shall include identification of the individual trees to receive tree care as per these guidelines. If any deviation from the approved plan details and specifications occurs, the contractor shall notify the qualified professional to determine what action should be taken.

Prior to any site disturbance, it shall be the responsibility of the contractor to install tree preservation measures in accordance with plans and specifications prepared by a qualified professional. It is the contractor’s responsibility to safeguard the trees designated to be preserved. Throughout planning and construction, applicants should monitor the effect of the proposed activities on the forest or tree retention area.


4.1 Concerns

Following is a list of concerns that should be monitored:

1. Soil and root compaction2. Root injury3. Limb or trunk injury4. Too much water5. Too little water6. Disease

The following must not occur within the tree protection area:

1. Stockpiling of soils2. Operating or storing construction equipment3. Burning in close proximity to protected areas4. Re-grading causing runoff, flooding, or change of

elevation5. Parking vehicles and storing supplies6. Spilling of toxic materials7. Spraying of herbicides in close proximity to

protected areas

4.2 Fines

Fines for noncompliance with the FCP and penalties for any trees lost or damaged due to negligence will be assessed according to the local governing agency’s regulations or the existing contract or agreement with the owner.

4.3 Forest and Tree Planting

The Forest Conservation Act also requires that the FCP include an afforestation or reforestation plan when appropriate. After techniques for retaining forest on a site have been exhausted, afforestation and reforestation may be required on the site or, if demonstrated as necessary, off the site. A final alternative may be a fee-in-lieu paid to the Forest Conservation Fund of the approving authority if an applicant demonstrated that the requirements for reforestation or afforestation on site or off site cannot be reasonably accomplished.

Specifications for the afforestation or reforestation will be on the FCP. The following scope of work and details will pertain mainly to tree preservation.

5.0 Scope of Work5.1 Tree Preservation Activities

For pricing purposes, all required tree preservation activities shall be outlined on the FCP or made as an

attachment on the proposal to the contractor from the owner or owner’s representative. Items listed in these specifications are examples of what should be done for proper tree preservation. All of these items may not be necessary; therefore, a list of activities to be priced and performed must be on the FCP or included as an attachment to the pricing document.

5.2 Industry Standards

All work performed shall meet or exceed industry standards approved by the International Society of Arboriculture (ISA), American National Standards Institute (ANSI), or the Tree Care Industry Association (TCIA).

5.3 Professional Arborist

The developer shall retain a professional arborist to ensure the proper implementation of the FCP. A “professional arborist” is defined as an arborist who has demonstrated his/her proficiency by obtaining a certification through the International Society of Arboriculture.

6.0 Implementation6.1 Tree Inventory

1. Tagging the tree with a numeric tree tag2. Location identified on design plan3. Identify the species4. Size, diameter, crown size and critical root zone5. Condition rating6. Additional information on any tree or groups of

tree or plants7. Identify defects such as decay, structural

deficiencies, etc.8. Recommendations for preservation9. Recommendations for mitigation activities once

development plans are finalized

6.2 Demarking Limits of Disturbance

The limits of clearing and grading shall be accurately flagged prior to any construction activity on site.

6.3 Clearing Operations

Trees to be removed shall be felled in such a manner as to preserve the trees that are to remain. Trees directly adjacent to the limits of clearing and grading, but within the limits of clearing and grading, shall be felled by hand, with a chain saw. If stumps must be removed, root prune around the back side (tree preservation side of


stump) before removal. Trees within the tree preservation areas, which are individually identified by the project arborist to be removed, shall be felled by hand, with a chain saw, and the stumps shall remain in place. If necessary, to ensure that the removal of these trees does not damage the trees designated to be preserved, some trees may need to be climbed and cut down in sections.

6.4 Root Pruning

Root pruning shall be performed whenever grades will be altered within the root zone of a tree to be preserved and shall be conducted at the limits of disturbance. Root pruning shall be performed using an air spade, vibratory plow, or trencher. If a trencher is used, the roots shall be clean-cut using the appropriate tool (i.e., hand saw, loppers, or hand pruners), and the trench shall be backfilled immediately to prevent root dehydration. Where cuts are to occur, root pruning shall be to a depth of 24 inches or to the depth of the excavation, whichever is less. Root pruning the trench may be used for the installation of a silt fence, if one is to be installed at the limits of disturbance. Root pruning shall be overseen by a certified arborist or their designated individual.

6.5 Tree Preservation Fencing

Fencing shall be installed at the limits of clearing and grading wherever clearing and grading is to occur within critical root zones of trees designated to be preserved. Fencing shall be installed prior to demolition or construction to prevent land-disturbing activities within the tree preservation area. Signs prohibiting entrance should be installed every 30 feet along fencing. Signs should read, “TREE PRESERVATION AREA – KEEP OUT”. The type of fencing required needs to be specified: 2"x4" welded wire on “T” posts with orange flagging ribbon for safety or 6’ chain link fence attached to ground driven posts.

6.6 Wood Chips or Mulch

Chips or mulch that is produced as a result of clearing operations on site may be used for this purpose. No engine-driven machinery may be used within the tree preservation area to place chips or mulch unless proper precautions are taken to protect critical root zones. Chips or mulch shall not be placed at a depth of more than six inches within the preservation areas.

6.7 Vertical Mulching

Trees designated to receive vertical mulching treatment shall be treated as soon after clearing and grading as weather permits. Vertical mulching should not be performed when soil is wet. Areas to be treated, hole

size and spacing, and backfill material (if any) shall be determined by the project arborist.

6.8 Fertilizer Application

Fertilizer application shall be performed in accordance with ANSI A300, Tree, Shrub, and Other Woody Plant Maintenance – Standard Practices (Fertilization). Trees designated for preservation as indicated in the Tree Preservation Activities Schedule shall receive fertilization. Specifications and the schedule should be developed by a person familiar with soils and plant nutrient requirements for that specific geographic area. Fertilizer should be a slow-release formulation.

6.9 Tree Pruning

Pruning shall conform to ANSI A300, Tree, Shrub and Other Woody Plant Maintenance Standard Practices (Pruning). Pruning prescriptions should be developed by a person familiar with tree species for the specific geographic area. Trees shall be pruned as indicated in the Tree Preservation Activities Schedule. Maintenance pruning shall consist of crown cleaning to remove all dead, damaged, and weak branches. The removal of selected conflicting branches shall be included. Under no circumstances shall the interior of trees be stripped. Interior branches shall be selectively pruned to reduced conflict or where branches are damaged. Hazard reduction pruning shall consist of the removal of any dead branches and the correction of any other problems related to safety. Items not correctable by pruning shall be brought to the owner’s and project arborist’s attention in writing.

6.10 Cabling and Bracing

Support systems are used to provide supplemental support to leaders, individual limbs, and/or the whole plant. Objectives for support systems shall be defined prior to installation. All prescriptions and recommendations should be provided by a person familiar with tree growth habits, weights, and wood strength. The implementation shall be in accordance to the ANSI A300 Standards Tree, Shrub, and Other Woody Plant Maintenance Standard Practices (Support Systems).

6.11 Lightning Protection

Lightning protection systems are used to safeguard trees from damage due to lightning. Much expense and effort is provided to preserve trees, and select specimen trees should be considered for protection against lightning. These systems should be installed in accordance with ANSI A300 Tree, Shrub and Other Woody Plant Maintenance Standard Practices (Lightning Protection Installation for Trees).



A pest management program should be developed to protect plants that may have been weakened due to land-disturbing activities. These plants may be more susceptible to disease and insects. Many trees have had roots removed, grades changed, and drainage patterns altered. These trees should be monitored for changes in condition, and proper prescriptions should be developed.

6.13 Watering

Supplemental watering may be necessary during drought conditions or when adequate water is not available. Trees that have roots and rooting areas damaged, changed, or removed must have a schedule for proper watering. Trenching for irrigation within the critical root zone shall be avoided to prevent further damage.

6.14 Monitoring/Follow-up Inspections

The amount of monitoring on site by an approved arborist during construction or the number of follow-up visits required after construction shall be detailed in the pricing document.

7.0 Construction DetailsPlease see the diagrams on the following pages. All of the details may not apply to your condition, so see your FCP for use of these details.

The drawings on the following pages are reprinted with permission of the Maryland Department of Natural Resources Forest Service from the State Forest Conservation Technical Manual, 3rd edition, 1997. To purchase a copy of this manual, call the Maryland Division of State Documents at (410) 974-2486.

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