IRRIGATION METHODSfor the Home Vegetable Garden

Presented by AFAC Walter Reed Garden Volunteers

Catherine Connor, Scott McAttee & David Sachs

4/11/2018

Acknowledgment Of Sponsors

2018 Garden Talks happen thanks to the collaboration of:

• “Plot Against Hunger Program” – Arlington Food Assistance Center

• Arlington Public Library – “Arlington Reads, Arlington Grows”

• Arlington Friends of Urban Agriculture

• Master Gardeners of Northern Virginia Volunteers

• Virginia Cooperative Extension Service – Arlington/Alexandria Office

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 2

What we’ll cover

Concepts:• Water Management Practices for the Home Vegetable Garden• Irrigation Practices at the Walter Reed Garden

• Gravity Fed Drip Irrigation System with Rain Barrels• Role of Irrigation Ollas as a Sub-Surface Irrigation Method

• Sub-Surface Irrigation Planters• Using 4 gal. & 5 gal. Double Buckets to Grow Foodstuff

Practice:• Make a Double Bucket Planter• Set Up a Drip Irrigation Line • Learn How to Make an Irrigation Olla with Unglazed Terra Cotta Pots

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 3

Water supports vital plant functions:

• Photosynthesis

• Support / rigidity / turgor

• Transpiration

• Transportation of nutrients and sugars to various plant parts

Vegetables Need at Least 1” of Water per Week

65 gallons per 100sqft

27’000 gallons per acre

Irrigation as a Water Deposit

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 4

Photo by Francesca York

Manage Irrigation to Supplement Nature in Meeting Plant Needs While Conserving Water

• Consider Climate (Arlington/Alexandria)• U.S. Department of Agriculture’s Plant Hardiness Zone 7a/b

• Average annual extreme minimum temps (7a: 0-5oF and 7b: 5-10oF)

• American Horticultural Society’s Plant Heat Zone 6 & 7 • Number of days >86oF in an average year (6: 40-60 ds/yr and 7: 61-90 ds/yr)

• Your Garden’s Microclimates• Sun exposure, heat sources, wind patterns, gardening methods, “effective” precipitations

• Consider Soil• Soil types affect drainage and available water capacity

• Consider Crops• Crops have different and changing water requirements based on varieties,

growth stage and root systems

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 5

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 6

http://www.plantmaps.com/6

EXTRA SLIDE 1 – Our Climate – Cold and HeatUSDA Plant Hardiness Zones- Average annual extreme minimum temps

AHS Plant Heat Zones– Number of days >86oF in an average year

Soil & Water Relationship

http://agriculture.vsu.edu/files/images/

special-programs/water-management-

for-raised-bed-gardens-revision.pdf

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 7

EXTRA SLIDE 2 – Soil, Water & Roots

Reprinted from dripworks.com

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 8

Approximately 70 percent of water used by plants is removed from the upper half of the plant root zone.

Typical water extraction pattern in uniform soil profile.

Irrigation Ideas from WRG – Central Library Garden Talk

EXTRA SLIDE 3 – Root Depth

http://extensionpublications.unl.edu/assets/pdf/g2189.pdf

4/11/2018 9

https://directives.sc.egov.usda.gov/OpenNonWebContent.aspx?content=17837.wba

EXTRA SLIDE 4 – Soil Depth Limitations

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 10

Soil drainage classification from BSE-194 – VT pub

USDA NRCS National Engineering Handbook – Irrigation Guide

Growth Stage & Crop Specific Requirements

In general, water is needed most for:

• germination of seeds (to 2-4 true leaves),

• immediately after transplanting,

• during the first few weeks of development while roots get established,

• during the development of edible storage organs.

Remember that there is such a thing as “too much water”

Critical periods for selected vegetables:

• Cauliflower: head development

• Cucumber: flowering, fruit development

• Eggplant: flowering, fruiting

• Lettuce: Head development; moisture should be constant

• Melons: Flowering, fruit development

• Tomato: Flowering, fruiting

• Peas: Pod filling

By knowing the critical watering periods for selected vegetables, you can adapt the amount of supplemental water you add.

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 11

http://msue.anr.msu.edu/resources/blossom_end_rot_tip_sheet

EXTRA SLIDE 5 – Gardening Methods

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 12

1. Watering Can

2. Hose (with some kind of nozzle)

3. Drip systems

4. Sub-Surface Irrigation

5. Sprinklers (overhead watering is not recommended – early morning)

Irrigation Methods for the Home GardenDOs and Don’ts

• Dispense H2O at the base of the plants – Avoid wetting the foliage• Wetting foliage wastes water and can lead to fungal diseases

• Apply H2O gently – Avoid splashing or splattering• Splattering can lead to soil borne diseases and erosion

• Check and monitor – Don’t assume everything is fine• Use your finger or a moisture meter in several places

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 13

Additional Water Conservation Strategies

COVER YOUR SOIL!

• Mulch

• Cover Crop / green manure

• Under-sow

PROTECT FROM HEAT & WINDS

• Wind Breaks

• Shade Cloth

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 14

Irrigation at theWalter Reed Garden

Gravity Fed Drip Irrigation

w/Rain Barrels as Reservoir

+ Ollas for Select Crops

Irrigation Ideas from WRG – Central Library Garden Talk4/11/2018

• Uses gravity to move water – no pump needed• Must select equipment correctly

• Must elevate reservoir and consider slope of the garden plot

• Moderately priced and effective for smaller sized crop areas• Keep it simple

• A water reservoir, a structure to support it, piping & shut off valve, drip lines, timer (optional) & filter

• When practical, fill the water reservoir with rain water harvesting techniques • Keep the reservoir opening covered with mesh material/screen

• Top the rain barrel with a collar to collect rain water (alternatively fill with city water)

Gravity Fed Drip Irrigation w/Rain Barrel Reservoir (1)

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 16

Screen WasherBuilt Into Timer

• Rain barrels are holding tanks for rain or city water. • Capped with a rain catching collar most of the year.• Plastic covers replace collars in summer heat to

minimize the growth of algae.

Our drip irrigation is controlled by timers. It is essential to select a timer specifically designed for a no-pressure (gravity fed) system.

Toro53746

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 17

Plan based on your unique situation

Consider slope, intended crop, cost, level of automation, etc.

Whatever your choices, select equipment designed for low/no pressure

• ½” main line tubing – may be run length or width of the bed to be watered

• Run the branch lines off the main line• ¼” soaker driplines come w/built-in emitters spaced every 6”, 9”, 12”

• Basic drip emitters at end of ¼” tubing water individual plants (peppers, zucchini, tomatoes)

• Secure the lines in place

• You will need miscellaneous tools

Gravity Fed Drip Irrigation w/Rain Barrel Reservoir (2)

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 18

Maintain the system

• Keep the filter clean

• Monitor for and remove algae development in the reservoir

• Check soil moisture in multiple locations and keep track of water dispensed

• Troubleshoot problems quickly• Check for and fix leaks in the drip system or with the barrel’s spigot

• Check emitters and lines for blockage

• Winterize the system (drain & store)

• Do season-start shores• Clean the rain barrels thoroughly

• Check the lines

Gravity Fed Drip Irrigation w/Rain Barrel Reservoir (3)

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 19

Ollas as A Sub-Irrigation Method

Olla irrigation is the most efficient method for maintaining soil moisture near field capacity and avoiding conditions of saturation or wilting point.

Edible garden plants that have optimum soil moisture exert less energy drawing water and nutrients from the soil, grow faster and are less stressed.

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 20

Ollas Take Many Forms

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 21

Ollas Are Buried in the Soil & Usually Given a Cover

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 22

Ollas Are Organized to Reach Plants Around Them

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 23

Ollas Need To Get Filled on A Regular Basis

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 24

You can Make an Olla With Terracotta Pots

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 25

Test your ollas for leaks before planting and

replanting each year!

You Can Automate Olla Irrigation

Walter Reed Garden plans to experiment with this in 2018

• Build smaller, fully sealed ollas.

• Connect them to a water source.

• Such pots can be completely buried.

• Have gravity fill the ollas.

• Replenish the water source container.

Thomas Bowes on YouTube

https://www.youtube.com/watch?v=mDn7vWwrYEc

https://www.youtube.com/watch?v=j0pwF-3VriA

https://www.youtube.com/watch?v=s0BryMMFwME

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 26

http://www.globalbuckets.org/

Double Buckets as A Sub-Irrigation Method

Sub-surface Irrigation Planters (SIP)

Rely on wicking and osmosis to provide plants with adequate moisture directly at the roots.

The top/inner bucket serves as a planter while the bottom/outer bucket serves as the reservoir.

Sometimes (erroneously) named “self-watering” these planters can come in many different sizes.

SIP can also be made with one container, where the water compartment is isolated from the planter segment by some kind of barrier.

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 27

https://en.wikipedia.org/wiki/Sub-irrigated_planter

https://extension.umd.edu/hgic/plants/self-watering-containers

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 28

Potatoes

Peppers

Eggplants

Tomatoes

Swiss Chard& Carrots

YOU CAN GROWMANY THINGS IN A

FOUR GALLON DOUBLE BUCKET!!!

Bush Beans

Upcoming Garden Talks

• April 18: Garden Structures for Support & Pest Control – Learn to support tomatoes, vines and other crops, increase growing space and keep out squirrels and other critters.

• April 25: Balcony & Container Gardening Basics – No room? No problem! Grow herbs, native plants, flowers and other edibles on your patio, balcony, front stoop, or back deck.

• May 2: Foraging for Wild Edibles – Find edibles in our urban area, bay foraging in our wild (and not so wild) areas.

• May 9: Tomatoes – Grow for Success – Tips and tricks for getting the best out of your tomato crop. Fertilizing, pruning and recognizing pests and diseases.

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 29

DOWNLOAD FILES FROM TODAY’S PRESENTATION

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 30

Visit AFAC’s Plot Against Hunger Gardening Resources at:

https://afac.org/plot-against-hunger/resources/

DOWNLOAD FILES FROM TODAY’S PRESENTATION

4/11/2018 Irrigation Ideas from WRG – Central Library Garden Talk 31

Or visit the public link: https://goo.gl/zDDy8h