of an osu master gardener diagnosing home gardener

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Diagnosing Home Gardener problemsand making recommendations

A day in the life…

of an OSU Master Gardener

The Desk:Homeowner Home and Garden advice

MG program began asa way to meet demandfor this information

Restricted to callsfrom non-commercialsources

Provide diagnosis andadvice within the officeor 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!

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

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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 Diagnosticshttp://www.dddi.org/OSU/index.cfm

Inquiries to avoid:1. Commercial operations…

• Size of operation• Is product being sold?

Refer these tocommercial 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 OregonEC 628: Soil sampling for home gardens and small acreages

Miscellaneous others

http://www.dddi.org/OsU/index.cfm

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Diagnosing plant problems

Neil BellOSU ExtensionMarion and Polk Counties

First, identify the plant

Flowering pear(Pyrus sp.)

• 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) Spruce (Picea sp.) and Russian Cypress (Microbiota decussata)

Western redcedar (Thuja occidentalis): foliar browning Dwarf Oregon Grape (Mahonia aquifolium ‘Compacta’)

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Rhododendron sp.

Crape myrtleLagerstroemia sp.

Tomato (Lycopersicon esculentum)

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

Arborvitae (Thuja occidentalis)

Dwarf Alberta Spruce (Picea glauca ‘Conica’)

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

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Boxwood (Buxus sempervirens), with Hebe (Hebe sp.)

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?

Red Alder (Alnus rubra)

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Normal

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

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Uniform pattern=abiotic factors (non-living)

Abnormal

Random pattern=biotic factors (diseases/pests)

Abnormal

Random pattern Occurs because of progressive spread of a living organism

Noble Fir (Abies nobilis)

Kinnikinnick (Arctostaphylos uva-ursi): Black Root rot? Turf: Cranefly (Tipula sp.) damage

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Arborvitae (Thuja occidentalis): spider mites

Don’t overanalyze “uniform” versus “random”

Arborvitae (Thuja occidentalis) near La Grande, OR

Japanese Cedar (Cryptomeria japonica)

Is the pattern… A. Uniform

B. Random

Turfgrass (unknown species)


B. Random

Kinnikinnick (Arctostaphylos uva-ursi ‘Massachusetts’)


B. Random

Rhododendron (Rhododendron spp.)

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B. Random

Boxwood (Buxus sp.)

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

Flowering Dogwood (Cornus florida)

Manzanita (Arctostaphylos x media): Leaf gall aphid (Tamalia cowenii)

Just leaves?

Red Maple (Acer rubrum): Anthracnose (Kabatiella sp.)

Apple (Malus sp):Scab (Venturia inaequalis)

Leaves and fruit?

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

Leaves, fruit and shoots?

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Blueberry (Vaccinium sp.): Mummyberry (Monilinia sp.) Cherry (Prunus avium), Coryneum blight (Wilsonomyces carpophilus))

Stem-tip dieback?

Atlas Blue Cedar (Cedrus atlantica ): Needle Blight (Sirococcus conigenus)

Individual stems dying back entirely?

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

Twig or branch dieback?

Black walnut (Juglans nigra): Thousand Cankers Disease (Geosmithia morbida) Cherry (Prunus sp.)

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The whole plant?

English Walnut (Juglans regia) Red Maple (Acer rubrum): Phytophthora Canker (Phytophthora sp.)

Birch: Betula utilis

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

Normal

Abnormal


Abnormal


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Dwarf Alberta Spruce(Picea glauca ‘Conica’): sunburn Rhododendron (Rhododendron sp.): Nitrogen deficiency

Cyclamen (Cyclamen sp.): leaf-edge chlorosis

Abnormal


Dwarf Alberta Spruce(Picea glauca ‘Conica’)

Weeping Cherry: (Prunus sp.)

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

Is the pattern…

A. Uniform

B. Random

Juniper (Juniperus sp.)

Is the pattern…

A. Uniform

B. Random

Boxwood (Buxus sp.)

Is the pattern…A. Uniform

B. Random

Hebe (Hebe ‘Emerald Gem’)


B. Random

English Yew (Taxus baccata)

7. What is the pattern on the plant part?

Normal

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Abnormal


Hosta: drought stressTomato (Solanum lycopersicum):blossom-end rot

Abnormal


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

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

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

Pear (Pyrus communis):Scab (Venturia pirina)

Normal

And on conifers….

Weeping baldcypress (Taxodium distichum ‘Cascade Falls’)

Abnormal


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Grand Fir (Abies grandis), Phenoxy herbicide damage

Abnormal


Douglasfir (Pseudotsuga menziesii): Needle cast (Rhabdocline spp.) Douglasfir (Pseudotsuga menziesii): Silver-spotted Tiger Moth (Lophocampa argentata)


B. Random

Pacific Dogwood (Cornus nuttalii)

Is the pattern…

A. Uniform

B. Random

Aspen (Populus tremuloides)

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Is the pattern…A. Uniform

B. Random

Apple (Malus domestica)


B. Random

Apple (Malus domestica)

8. When did the symptoms appear?

Alstroemeria (Alstroemeria sp.): Frost damage Photo: Luanne Whitaker

Symptoms appear early in the year?

Rosemary (Rosmarinus officinalis): cold injury Cherry Laurel (Prunus laurocerasus)-Shothole (Thyrostroma carpophilum)

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Viburnum tinus-sunburn

Symptoms appear later in the year

Lilac (Syringa vulgaris):Powdery Mildew (Erysiphe syringae)

Arborvitae (Thuja occidentalis): spray damage by horticultural oil

Symptoms appear after specific event 9. Are the symptoms spreading, improvingor constant?

2007 2009

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

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Common Lilac(Syringa vulgaris) Common Lilac (Syringa vulgaris)

Common Lilac(Syringa vulgaris) Cherry (Prunus sp.)

Symptoms stay the same

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

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Rhododendron (Rhododendron sp.):Sunburn

Damage from non-livingfactors will induce symptomdevelopment, but there willbe no signs of a pest

10. Are any signs of a pest present?Symptoms: Physical characteristics of a problemexpressed 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 (Pseudomonas savastanoi) Oak (Quercus sp.): mite galls

Alder (Alnus rubra): cankers (undetermined cause) Peach (Prunus persica): dieback and canker

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Tomato (Lycopersicon esculentum): rot caused by Late Blight (Lycopersicon esculentum)

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.)

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Incense-cedar (Calocedrus decurrens):Broom rust (Gymnosporangium libocedri) 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)

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Viburnum davidii: leaf notching due to root weevils Colorado Blue Spruce (Picea pungens): White Pine weevil (Pissodes strobi)

Colorado Blue Spruce (Picea pungens):White Pine weevil (Pissodes strobi)

Colorado Blue Spruce (Picea pungens): White Pine weevil (Pissodes strobi)

Apple: (Malus domestica): frass of the Apple-and-thorn skeletonizer (Choreutis pariana) Hosta: slug trails

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Vole burrows

Some signs cannot be seen without magnification

Red raspberry (Rubus idaeus): RBDV

‘Brooks’ Plum (Prunus domestica): possible Bacterial canker (Pseudomonas syringae)

Pear (Pyrus communis): Leaf spot-undetermined cause

• Plant Disease Control:• PNW Disease Management Handbook

http://pnwhandbooks.org/plantdisease/

• Insect Pest Control:• PNW Insect Management Handbook

https://pnwhandbooks.org/insect

• Weed Control:• PNW Weed Management Handbook

http://pnwhandbooks.org/weed/

Websites for home garden problems

Pesticide recommendations for homeowners




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Common cultural and environmental problems inthe garden and how to recognize them

Neil BellOSU Extension ServiceMarion and Polk Counties

• Planting practices

Cultural causes of plant problems

• Herbicide injury

• Pruning injury

• Root damage

• Rootbound plants

White-bark birch (Betula jacquemontii)

Root-bound plants

Fig (Ficus carica): circling roots

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Deodar cedar (Cedrus deodara)

European White Birch (Betula pendula)Western Juniper(Juniperus occidentalis)

Deodar cedar (Cedrus deodara)

Pruning problems

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Rockrose (Cistus x hybridus) Oriental Arborvitae: Platycladus orientalis

Pesticide injury

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

Bearded Iris (Iris sp.):glyphosate damage Oak leaf Hydrangea (Hydrangea quercifolia): phenoxy herbicide damage

Pine (Pinus sp.)Phenoxy herbicide damage Deodar Cedar (Cedrus deodara): phenoxy herbicide damage

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Rose (Rosa sp.): acetic acid herbicide injury

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

Cold Injury

Cold injury results from:

• Unexpected frosts

• Winter low temperatures

Rare to see winter injuryto deciduous shrubs andtrees or conifers

Port Orford Cedar(Chamaecyparis lawsoniana)

Shrub dogwood (Cornus sericea ‘Kelseyi’)Coyote brush (Baccharis pilularis)

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Mexican orange (Choisya ternata) Marion trailing blackberry (Rubus ‘Marion’)

Apple (Malus domestica)English yew (Taxus baccata): snow damage

Frost damage

Photos: B. StrikStrawberry (Fragaria x ananassa)

Pollination problems

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

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Zucchini (Cucurbita pepo) Grape (Vitis sp.)

Too much or too little sun

Vine maple (Acer circinatum)

Distinguish between excess sun (sunburn)and drought stress

Sunburn occurs when a plant, or plant partis exposed to too much sun and heat, evenif well-supplied with water

Drought stress occurs to any plant when soilwater becomes limiting

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

Rhododendron: (Rhododendron sp.)

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Japanese barberry (Berberis thunbergii): yellow-foliaged cultivar

Hosta sp.: sunburn Flowering dogwood (Cornus florida): heat?

Sunburn on flowers

Mophead Hydrangea (Hydrangea macrophylla)

Sunburn on fruit

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Red Maple (Acer rubrum) Atlas Cedar (Cedrus atlantica ‘Glauca Pandula’): winter sunburn?

Lack of sun can cause problems…

Flowering dogwood:(Cornus canadensis) Flowering dogwood (Cornus florida)

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Mugo Pine:(Pinus mugo)

Too much or too little waterDrought 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)

Hebe sp.

• Drooping foliage

• Tip burn

• Brown areas on leaves

• Loss of older leaves

• Shoot dieback

Symptoms of drought stress

Pacific Dogwood (Cornus nuttalli)

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Red Alder (Alnus rubra): drought stress

Katsura tree:(Cercidiphyllum japonicum)

Rhododendron (Rhododendron sp.)

Ponderosa PinePinus ponderosa Douglasfir (Pseudotsuga menziesii)

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Drainage Problems

Drainage problemsresult from:

• Topography

• Impervious soil

Leyland Cypress:(x Cupresssocyparis leylandii)

Boysenberry (Rubus ‘Boysen’)

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

Nutrient deficiencies in plants

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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)

Mobile nutrient: symptoms at plant base

Flowering plum (Prunus x blireana)

Mobile nutrient: Nitrogen deficiency

Japanese Fatsia (Fatsia japonica ‘Variegata’)

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Rhododendron (Rhododendron sp.): Nitrogen deficiency

Turf: Nitrogen deficiency

Immobile Nutrient: Iron

Rhododendron (Rhododendron sp.): pH-induced Fe deficiencyNeolitsea sericea

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Blueberry (Vaccinium corymbosum: pH-induced Fe deficiency Apple (Malus domestica): bitter pit

Immobile Nutrient deficiency in fruit: Calcium

Tomato (Lycopersicon esculentum):Blossom end rot

Salt toxicity

Winged Euonymus (Euonymus alatus): salt toxicity

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Wind

Hardy Kiwifruit (Actinidia arguta): scarred fruit

Hail

Highbush blueberry (Vaccinium corymbosum): hail damage

Apple (Malus domestica):Hail damage

Douglasfir (Pseudotsuga menziesii): Lightning damage

• Plant Disease Control:• PNW Disease Management Handbook


• Insect Pest Control:• PNW Insect Management Handbook


• Weed Control:• PNW Weed Management Handbook


Websites for home garden problems

Pesticide recommendations for homeowners




of an osu master gardener diagnosing home gardener

Documents