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Diagnosing Home Gardener problems and making recommendations

A day in the life…

Of an OSU Master Gardener

The Desk: Homeowner Home and Garden advice

MG program began as a way to meet demand for this information

Restricted to calls from non-commercial sources

Provide diagnosis and advice within the office or by phone

A few weeks training…

Then off to the front lines!

Two big advantages…

1. It’s free! 2. Talk to an actual person

Requests are either…

Phone calls (or e-mail)

Visits to the office

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Requests for information are usually:

1. Plant identification Ornamentals Weeds Apple/pear/plum variety

2. Insect Identification

3. Pests in the home ants (carpenter, sugar) termites pests of stored products spiders!

Lawns Pruning propagation

4. Critter problems Deer control

voles

moles gophers

6. Plant problems (including lawns) Cultural Disease Insect pest Herbicide damage

5. Requests for cultural information Tree fruit Small fruit Ornamentals

Difficulties:

1. Client may only tell you so much

2. You cannot visit

The resources we use are…

Books

Web-based

What kind of information do we give out?

Verbal: Information just over the phone

Photocopies of book chapters

OSU publications • Printed from the web • Hard copies from office files

http://extension.oregonstate.edu/catalog/

MG volunteer

Community Horticulturist

Crop Specialist

You don’t have to do it all by yourself!

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So if you are in doubt…

Leave it for me!

Insects (and spiders): • Insect ID clinic • No charge per sample

Plant Disease: • Plant Disease Clinic-Melodie Putnam • $50 charge per sample

Plant ID: • OSU Herbarium-Dr. Richard Halse • No charge per sample

We also can use other faculty and clinics…

Also: Distance Diagnostics http://www.dddi.org/OSU/index.cfm

Inquiries to avoid: 1. Commercial operations…

• Size of operation • Is product being sold?

Refer these to commercial agents!

Others…

2. Human health issues • Poisonous plants

3. Legal disputes

house calls

Soil or water tests

Things we do not do…

EM 8677: Laboratories serving Oregon EC 628: Soil sampling for home gardens and small acreages

Miscellaneous others

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Plant Identification Most of samples brought in are from gardens • People with new gardens

• Seedling plants that appear • Weed samples-how to eliminate!

ID not possible? Leave for me!

OSU plant ID website: http://oregonstate.edu/dept/ldplants/

Lonicera pileata

You should have:

More than one leaf!

Flowers or fruit best!

Some samples are more common than others

Catalpa

Paulownia

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Weed identification

Japanese knotweed

Same sample required

Announcements in paper Of “noxious weeds” bring enquiries

Mushroom ID-a special case

Most people want to know: • Is the mushroom edible/poisonous • How to eradicate from lawn/garden

Rake mushrooms up

Slime mold (Fuligo sp.) Aleria aurantia

Oregon mycological society http://www.wildmushrooms.org/

Leave ID questions for me…

• I take digital pics • Email to campus

Willamette Valley Mushroom Society http://mushroom.byethost12.com/

Moss and lichen

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Moss and Lichens are not pathogenic

Living with mosses http://bryophytes.science.oregonstate.edu/mosses.htm

Moss in the lawn

FS 55: Controlling moss in lawns

Scholars Archive http://ir.library.oregonstate.edu/xmlui/

Insect and Spider ID

Scale insects on Wisteria

Household pests

Human health: • Cockroaches

• Fleas

Structural: • Termites

• Carpenter ants

Stored products: • Moths • Carpet beetles

Nuisance: • Lady beetles • Sugar ants • Box elder beetles

Samples of the insect and plant (if applicable) are essential for proper ID

You’ll usually need adults • Larvae are very difficult

Ken Gray Images: http://www.ipmnet.org/kgphoto/

http://entomology.oregonstate.edu/urbanent

OSU Urban Entomology

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Cockroaches: Often associated with apartments

Health pests

Fleas American cockroach

German cockroach

Structural pests

Carpenter ant

Termites

Require referral to PCO: “Pest” in yellow pages

Pests of stored products

Indian meal moth

Carpet beetles

Lady beetle

Box Elder bug

Nuisance insects

Household insect references of choice Take a Closer Look!

Common Sense Pest Control

http://www.puyallup.wsu.edu/plantclinic/resources/pls-res.html

http://entomology.oregonstate.edu/urbanent

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Information to get:

• Where was sample found? (on plant, soil or…)

• When was it noticed?

• What is damage (if any)?

• Any control measures used?

Garden insect problems

Rose aphids

Aphids on Plum

http://insects.ippc.orst.edu/pnw/insects

http://swd.hort.oregonstate.edu/

Spotted-wing drosophila Spiders in the home

Maybe spiders have earned a bad rep for some reason?

Only two venomous spiders in Oregon: • Black Widow • Hobo (Aggressive House Spider)

Most clientele want to know if it is venomous

Black Widow Aggressive House (Hobo)

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Most spiders brought in are neither species

Jumping Zebra Spider

Spider ID not always easy • if it can be readily ID’d, do so • if it cannot be, do not!

WSU http://cru.cahe.wsu.edu/CEPublications/eb1548/eb1548.html

General information on spiders, management:

http://gardening.wsu.edu/library/inse005/inse005.htm

ODA http://oregon.gov/ODA/PLANT/IPPM/spiders.shtml

The important facts are:

• Spiders with few exceptions are non-toxic beneficials • Sanitation and structural modifications work best

Vertebrate pests

Tree squirrel

Mole

Gopher

Climbing and burrowing pests

Voles

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Diagnosing plant problems

Two factors that affect ability to diagnose problems:

1. The perception of the caller of the problem

2. Their ability to describe the problem accurately

An accurate diagnosis depends on good information…

“Bring in a sample”

Better, much better…

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Photos give you an even better “picture”!

Encourage clients to bring in pictures

Deodar Cedar (Cedrus deodara)

Sometimes, a diagnosis is elusive…

Site visit required

What is the identity of the affected plant?

Steps in diagnosing plant problems…

Euonymus spp. Powdery mildew

Keep assessments of “damage” in proportion

Zucchini (Cucurbita pepo)

Zucchini (Cucurbita pepo)

• What are the characteristics of the plant?

• How does it display them through the year?

1. Determine that a “real” problem exists

Japanese Cedar (Cryptomeria japonica ) with Incense Cedar (Calocedrus decurrens)

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Pinus contorta ‘Chief Joseph’ Western redcedar (Thuja occidentalis): foliar browning

Pinus sp.

Crape myrtle Lagerstroemia sp.

Grape-pith color

Double file Viburnum (Viburnum tomentosum)

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Tomato (Lycopersicon esculentum)

2. What is the “population” of the plants?

Arborvitae (Thuja occidentalis)

The “population” refers to the number of plants of the species of interest that are present

Wheat (Triticum aestivum)

Boxwood (Buxus sempervirens), with Hebe (Hebe sp.) Highbush blueberry: Vaccinium corymbosum

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Azalea cultivars (Rhododendron spp.): Powdery mildew (Erysiphe azaleae)

Kinnikinnick (Arctostaphjylos uva-ursi)

3. And…how many of the plants are affected?

Turfgrass: undetermined problem

4. What is the pattern of damage within the population?

Incense Cedar (Calocedrus decurrens)

Normal

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Uniform pattern=abiotic factors (non-living) 1. Entire population uniformly affected

Abnormal

Usually the result of non-living, environmental causes

Uniform pattern

Occurs over the entire population of plants, or discrete groups

Periwinkle (Vinca minor)

Uniform pattern=abiotic factors (non-living) 2. Same part of entire population affected

Abnormal

Arborvitae (Thuja occidentalis)

Foliar browning on Pinus, Rhododendron and Euonymus

Uniform pattern=abiotic factors (non-living)

Abnormal

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Random pattern=biotic factors (diseases/pests)

Abnormal

Random pattern

Occurs because of progressive spread of a living organism

Oriental Arborvitae (Platycladus orientalis): Berckmann’s Blight Turf: Cranefly (Tipula sp.) damage

Arborvitae (Thuja occidentalis): spider mites Horsetail (Equisetum arvense) and oxalis (Oxalis sp.) weeds in flower bed

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Don’t overanalyze “uniform” versus “random”

Arborvitae (Thuja occidentalis) near La Grande, OR Petunia (Petunia x hybrida)

Japanese Cedar (Cryptomeria japonica)

Uniform or non-uniform?

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5. What part or parts of the plant are affected?

Japanese Zelkova (Zelkova serrata) Manzanita (Arctostaphylos ‘Arroyo Cascade’): Leaf gall aphid (Tamalia cowenii)

Just leaves?

Red Maple (Acer rubrum): Anthracnose (Kabatiella sp.) Apple (Malus sp): Scab (Venturia inaequalis)

Leaves and fruit?

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Blueberry (Vaccinium corymbosum): Mummyberry (Monilinia vaccinii-corymbosi)

Leaves, fruit and shoots?

Cherry (Prunus avium), Coryneum blight (Wilsonomyces carpophilus))

Stem-tip dieback?

Atlas Blue Cedar (Cedrus atlantica ): Needle Blight (Sirococcus conigenus) Cherry (Prunus sp.)

Individual stems dying back entirely?

Japanese Maple (Acer palmatum): Verticillium wilt (Verticullium dahliae)

The whole plant?

English Walnut (Juglans regia)

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Red Maple (Acer rubrum): Phytophthora Canker (Phytophthora sp.) Birch: Betula utilis

Silk Tree (Albizia julibrissin) Nectria canker

6. What is the pattern of damage within the plant…

Normal

Abnormal

Uniform pattern=abiotic factors (non-living)

Abnormal

Uniform pattern=abiotic factors (non-living)

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Dwarf Alberta Spruce (Picea glauca ‘Conica’): sunburn Rockrose (Halimium sp.): early-season tip chlorosis

Abnormal

Random pattern=biotic factors (diseases/pests)

Noble Fir (Abies nobilis)

Rhododendron: Root Rot (Phytophthora sp.)?

Hawthorn (Crataegus laevigata): Leaf spot (Diplocarpon mespili)

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7. What is the pattern on the plant part?

Normal Abnormal

Uniform pattern=abiotic factors (non-living)

Hosta: drought stress

Tomato (Solanum lycopersicum): blossom-end rot

Abnormal

Random pattern=biotic factors (diseases/pests)

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Rhododendron (Rhododendron sp.): Powdery mildew (Eriysiphe azaleae)

Beets (Beta vulgaris ): Leafminer (Pegomya sp.)

Maple (Acer sp.): Bladdergall mite (Vasates quadripedes)

Grape (Vitis sp.): Powdery mildew (Erysiphe necator)

Normal

Weeping baldcypress (Taxodium distichum ‘Cascade Falls’)

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Abnormal

Uniform pattern=abiotic factors (non-living)

Grand Fir (Abies grandis), Phenoxy herbicide damage

Arborvitae (Thuja occidentalis): Phenoxy herbicide damage

Abnormal

Random pattern=biotic factors (diseases/pests)

Douglasfir (Pseudotsuga menziesii): Needle cast (Rhabdocline spp.) Hemlock (Tsuga sp.): Hemlock woolly adelgid (Adelges tsugae)

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8. When did the symptoms appear?

Peach (Prunus persica): Leaf Curl (Taphrina deformans)

Symptoms appear early in the year?

Rosemary (Rosmarinus officinalis): cold injury

Ash (Fraxinus sp.)-Anthracnose (Gnomoniella fraxini) Viburnum tinus-sunburn

Symptoms appear later in the year

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Symptoms appear after specific event

Wheat (Triticum aestivum): spray damage

9. Are the symptoms spreading, improving or constant?

2007 2009

Port Orford Cedar (Chamaecyparis lawsoniana): Phytophthora root rot (Phytophthora spp.) Aspen (Populus tremuloides) Leaf scorch

Symptoms stay the same

Rosa Berries ‘N’ Cream™ Rhododendron (Rhododendron sp.)

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Rhododendron (Rhododendron sp.): Sunburn

Damage from non-living factors will induce symptom development, but there will be no signs of a pest

10. Are any signs of a pest present? Symptoms: Physical characteristics of a problem expressed by the plant.

Include: • wilting • leaf discoloration • leaf spots

• leaf distortion • defoliation • galls • cankers • rots/dieback • “plant decline”

Cucumber (Cucumis sativus): wilt

Holly (Ilex sp.): leaf discoloration Western Spicebush (Calycanthus occidentalis): leaf spots

Redbud (Cercis canadensis): Leaf distortion due to phenoxy herbicide European Pear (Pyrus communis): Fruit distortion due to true bug feeding damage

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Fraser Photinia (Photinia x fraseri): defoliation by Leaf Spot (Diplocarpon mespili) Birch (Betula sp.): gall Forsythia (Forsythia sp.): Stem Gall (Psudomonas savastanoi)

Oak (Quercus sp.): mite galls Alder (Alnus rubra): cankers (undetermined cause)

Peach (Prunus persica): dieback and canker Tomato (Lycopersicon esculentum): rot caused by Late Blight (Lycopersicon esculentum)

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Kousa dogwood (Cornus kousa) Plant decline

Goldenchain tree (Laburnum x watereri): aphids

Signs: evidence of the actual causal agent

Diseases: • fungal fruiting bodies

• fungal mycelia • bacterial slime (more later…)

Other… • rodent mounds/holes

• slug trails

Insects: • the insect itself

• boring holes or tunnels • sawdust • frass…

Apple (Malus domestica): Crane fly (Tipula sp.) Sunflower (Helianthus annuus): Sclerotinia wilt (Sclerotinia sclerotiorum)

Apple (Malus domestica): Rust (Gymnosporangium sp.) Incense-cedar (Calocedrus decurrens): Broom rust (Gymnosporangium libocedri)

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Big-leaf maple (Acer macrophyllum): Tar spots (Rhytisma punctatum) Cherry (Prunus sp.): possible Bacterial canker damage (Pseudomonas syringae)

Apple (Malus domestica): Leaf roller (species undetermined) Rhododendron (Rhododendron sp.): Azalea Lace Bug (Stephanitis pyrioides)

Hebe (Hebe sp.): Meadow spittle bugs (Philaenus spumarius) Viburnum davidii: leaf notching due to root weevils

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Colorado Blue Spruce (Picea pungens): White Pine weevil (Pissodes strobi) Apple: (Malus domestica): frass of the Apple-and-thorn skeletonizer (Choreutis pariana)

Slug trails Vole burrows

Some signs cannot be seen without magnification

Red raspberry (Rubus idaeus): RBDV Sweet Cherry (Prunus avium): possible Bacterial canker (Pseudomonas syringae)

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Pear (Pyrus communis): Leaf spot-undetermined cause

• Planting practices

Cultural causes of plant problems

• Herbicide injury

• Pruning injury

• Root damage

• Rootbound plants

White-bark birch (Betula jacquemontii)

Root-bound plants

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Flowering cherry (Prunus sp.): circling roots Deodar cedar (Cedrus deodara)

European White Birch (Betula pendula)

Western Juniper (Juniperus occidentalis) Deodar cedar (Cedrus deodara)

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Problems caused by pruning

English Laurel (Prunus laurocerasus) Rockrose (Cistus x hybridus) and California Lilac (Ceanothus ‘Victoria’)

Pesticide injury

Hebe (Hebe sp.): glyphosate damage Raspberry (Rubus idaeus): glyphosate damage Photo: B. Strik

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Bearded Iris (Iris sp.): glyphosate damage

Oak leaf Hydrangea (Hydrangea quercifolia): phenoxy herbicide damage Deodar cedar (Cedrus deodara): phenoxy herbicide damage

Arborvitae (Thuja occidentalis): spray damage by horticultural oil

Environmental causes of problems

• Cold Injury

• Wind/hail/lightning

• Water (too little or too much)

• Sun (too much or too little)

• Pollination problems

• Nutrient deficiencies

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Cold Injury

Cold injury results from:

• Unexpected frosts

• Fall or early spring low temperatures

• Winter low temperatures

Rare to see winter injury to deciduous shrubs and trees or conifers

Winged Euonymus (Euonymus alatus) Port Orford Cedar (Chamaecyparis lawsoniana) Coyote brush (Baccharis pilularis)

Oregon grape (Mahonia aquifolium) Mexican orange (Choisya ternata)

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Marion trailing blackberry (Rubus ‘Marion’) Escallonia

Maple (Acer sp.): south-west injury

English yew (Taxus baccata): snow damage Pineapple Broom (Cytisus battandieri): freezing rain

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Fall or early Spring freezes

Hebe ‘Andersonii Variegata’ Kiwi fruit (Actinidia deliciosa): frost damage to shoots

Blueberry (Vaccinium corymbosum): Frost injury

Photo: B. Strik

Frost damage

Photos: B. Strik Strawberry (Fragaria x ananassa)

Normay Maple (Acer platanoides)

Pollination problems

Honeybee (Apis mellifera) on blueberry flowers (Vaccinium corymbosum)

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Grape (Vitis sp.) Squash (Cucurbita pepo)

Impacts of other environmental factors: Too much or too little sun Distinguish between excess sun (sunburn)

and drought stress

Sunburn occurs when a plant, or plant part is exposed to too much sun and heat, even if well-supplied with water

Drought stress occurs to any plant when soil water becomes limiting

Sunburn can occur on leaves, flowers, fruit or stems…

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Rhododendron: (Rhododendron sp.)

Sunburn on flowers

Mophead Hydrangea (Hydrangea macrophylla)

Sunburn on fruit Lack of sun can cause problems…

Flowering dogwood: (Cornus canadensis)

Mugo Pine: (Pinus mugo)

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Drought stress is dependent on:

• Inherent drought tolerance of plant

• Soil conditions (moisture, structure etc.)

• Irrigation (and it’s efficacy)

• Site exposure and aspect

• Weather conditions (temperature, wind)

Weather: Temperature and wind

Site exposure Site aspect

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Soil conditions

“Irrigation” can mean many things…

Hebe sp.

• Drooping foliage

• Tip burn

• Brown areas on leaves

• Loss of older leaves

• Shoot dieback

Symptoms of drought stress

Pacific Dogwood (Cornus nuttalli)

Katsura tree: (Cercidiphyllum japonicum)

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Rhododendron (Rhododendron sp.) Coast Redwood (Sequoia sempervirens)

Rhododendron (Rhododendron sp.)

Turf: most enquiries in late summer

Turf: perennial ryegrass (Lolium perenne)

White-barked birch (Betula jacquemontii)

Drainage Problems

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Drainage problems result from:

• Topography

• Impervious soil

Leyland Cypress: (x Cupresssocyparis leylandii)

Boysenberry (Rubus ‘Boysen’)

Raspberry (Rubus idaeus): Phytophthora root rot (Phytophthora spp.)

Impervious soil layers: Soil preparation Overwatering?

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Nutrient deficiencies in plants

Dicentra spectabilis ‘Gold Heart’

Major nutrients:

Minor nutrients:

Also: salt toxicity….

Nutrients required by plants

Nitrogen (N) Phosphorus (P) Potassium (K)

Calcium (Ca) Magnesium (Mg) Sulfur (S)

Iron (Fe) Zinc (Zn) Manganese (Mn) Copper (Cu)

Molybdenum (Mo) Boron (B) Chlorine (Cl)

Base of plant – mobile (N, P, K, Mg)

Location of symptoms:

Top of plant – immobile (Ca, Fe, Mn, Zn, Cu, B)

Whole (mid) plant – partially mobile (S, Mo)

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Mobile nutrient: symptoms at plant base

Flowering plum (Prunus x blireana)

Mobile nutrient: Nitrogen deficiency

Tomato (Lycopersicon esculentum) Highbush blueberry (Vaccinium corymbosum)

Immobile Nutrient: Iron

Rhododendron (Rhododendron sp.): pH-induced Fe deficiency

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Pear (Pyrus communis): cork spot

Immobile Nutrient deficiency in fruit: Calcium Wind

Hardy Kiwifruit (Actinidia arguta): scarred fruit

Hail

Highbush blueberry (Vaccinium corymbosum): hail damage

Apple (Malus domestica): Hail damage Douglasfir (Pseudotsuga menziesii): Lightning damage

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• Plant Disease Control: • PNW Disease Management Handbook

http://pnwhandbooks.org/plantdisease/

• Insect Pest Control: • PNW Insect Management Handbook

http://insects.ippc.orst.edu/pnw/insects

• Weed Control: • PNW Weed Management Handbook

http://pnwhandbooks.org/weed/

Websites for home garden problems

Pesticide recommendations for homeowners

The End!