When starting your home orchard, make sure you: 

Choose disease resistant fruit tree varieties when possible.

Monitoring your orchard for bud and blossom stages is the key to good dormant spray (proactive) timing.

Monitoring your orchard for problems as they arise is key to good pest management.

Know why you are spraying! Some sprays recommended here are proactive- trying to prevent common problems through maintenance. Beyond general maintenance (dormant) spraying, never spray without identifying the problem.

When mixing spray solutions, always mix less than you think you will need, as disposal of the leftovers is difficult. Try spraying just water on your orchard to see how much will give you good coverage.

Always follow the directions on the container label. If the label is missing or unreadable, contact the company for directions (most pesticide labels are available online).

Many insect pests have natural controls in the form of beneficial insects. Avoid using broad spectrum insecticides if possible. If they are necessary, spray at dawn or dusk to limit the impact on bees and other beneficial insects.

Links throughout the page take you to two valuable information sites:

PNW Pest Management Handbook, an important pest and disease management web page that is focused on the Pacific Northwest. This is a joint effort of agricultural extension scientists from Oregon State University, Washington State University, and the University of Idaho. Used mostly by commercial growers, it has a wealth of information on life cycles of pests and diseases, and both conventional and organic treatments.

WSU Extension Hortsense, which is a home gardener focused compilation of fact sheets for managing common landscape and garden plant problems.

Fruit trees as we know them today have gone through centuries of selection. Because they were developed for fruit quality and production, many of their natural resistances to pest and diseases have been lost.

The home orchardist has the goal of keeping their trees healthy and productive. Because of the challenges of our climate, you will need to do some sprays, especially on young trees. You can grow healthy trees using organic methods, but to be successful, you need to be proactive. Organic disease control needs to be in place before the infection occurs.

Especially for young trees, repeated ‘misses’ on your timing can lead to stunted trees and blind wood (no fruit buds). Learning to use bud stages and heat units to time your controls is important, especially when using organic sprays. Online decision making tools/websites are very valuable in helping you target your strategies:USPest.org – this site uses weather stations to run disease and pest models and help you make decisions on when to spray. It is worth spending time here, learning to use the models. It will let you set up the models that work for your orchard, using the weather stations closest to you. We have a tutorial on using this valuable tool that walks you through the set up. For most home orchards, look at the models for:

1. 1. Apple Scab
   2. Pear Scab
   3. Codling Moth
   4. Apple Maggot

Ag Weather Net – this site is run by WSU, and uses just the Ag Weather stations throughout WA state. It requires registration to use, and many of the models require a subscription. For some homeowners, there will not be a weather station close enough to you to make this site useful (weather stations are only located in prime agricultural land areas).

When planting new trees, try to choose disease resistant varieties. Look for scab and mildew resistance in apples and pears, and leaf curl resistance in peaches. Later blooming sweet cherries and all tart cherries are easier to grow in frost prone sites.

Organic Products for Fungal and Bacterial disease control

Micronized Sulfur– available as powder and occasionally liquid concentrate form.

1. 1. Use with oil for delayed dormant sprays on pears and apples, controls powdery mildew, between stages 4 and 6
   2. Use for scab control on apples and pears, at pre-pink and petal fall
   3. Use with oil at leaf fall to control blister mite on pears
   4. Use at shuck fall (just after petal fall) on plums to help control black knot

Copper, as copper sulfate or copper soap

1. 1. Use at stage 3, combined with oil, on cherries, peaches and apricots, to control blossom blight and brown rot. The oil will smother overwintering aphid and mite eggs
   2. Use with a sticker at leaf fall on stone fruits to protect against bacterial canker, and on pome fruits to protect against anthracnose and pseudomonas canker.

Serenade/Sonata and Monterey Complete Disease Control– bacterial based fungicides that provides some control against fungal diseases, and unlike copper, can be used on actively growing trees.

1. 1. Powdery mildew on pome fruits
   2. Brown rot on stone fruits
   3. Pear blister rust (not complete control, some suppression)

Organic Products for Pest Control

Horticultural oils, either mineral or vegetable based, are effective at smothering overwintering eggs of aphids and mites. They need full contact/coverage to work, and if used during the growing season can cause foliage and/or flower burn on some varieties

Horticultural soap is used to control soft bodied insects such as aphids during the growing season. They need repeat applications to work.

Bacillius thuringiensis (Bt) is a bacterial control for the larval stages of many moths. The main use in the home orchard is to control leaf roller on apples and pears. Add this to your delayed dormant and first scab sprays to get the early hatch. This product can also be used for the early stages of webworm outbreaks.

Spinosad is also bacteria based, but broader spectrum. It is toxic to bees, so do not use it when bees are active. It is effective on codling moth, and somewhat effective on apple maggot. There is a danger of overuse, leading to resistant pests, so should be used with caution.

Codling Moth virus (Cyd-X, Carpovirusine, Virosoft) is a virus based control for codling moth only. Timing is crucial, and it is an expensive product.

PyGanic is formulated on an extract of the daisy Pyrethrum, creating a powerful broad spectrum insecticide. It is very toxic to bees and other beneficial insects as well as pest insects, so should be used with caution.

Mycotrol is a fungal based insecticide that is effective against aphids and leaf hoppers. Expensive and hard to find locally.

Neem oil based insecticides, including Azadirect are effective on some insects including SWD, pear slug, apple maggot, and cherry fruit fly.

Kaolin clay can “hide” the tree and fruit from insect pests, by coating the leaves and developing fruit with a material that is irritating to the flies and moths. This product is most commonly used to control Apple Maggot. It needs to be reapplied often to be effective.

Using bud stages to time sprays

Observing the bud development stages of fruit trees from dormant to full bloom is the key to proactive disease and pest management. Timing your sprays to bud stage allows you to spray less and get better control. Following the bud stage chart, we have suggestions for specific timings of disease controls. Most organic disease control sprays are prophylactic- the spray must be on the tree before the fungal or bacterial infections occur.