If you have backyard fruit trees you must begin the annual spraying routine. It is required for apples and cherries.


Bonnie Orr, WSU Master Gardener

With annual spraying, your other fruit trees will be healthier and your fruit will be more pleasing. Apples, cherries and pears are major agricultural crops in this area. An untreated back yard tree can damage the fruit in a commercial orchard.

People often say, “There are no orchards near me, so I don’t have to worry.” But insects can fly or be blown by the wind for miles.

You can treat your trees with conventional or organic materials. There are three types of spray schedules: Dormant, delayed dormant and growing season. The WSU Master Gardeners have spray schedules with suggested spray materials. You can request the information by emailing chelan mastergardeners@gmail.com. Provide a phone number in the e-mail so we can contact you and answer your questions. You can stop by at 400 Washington St. or call 667-6540 on Mondays and Wednesdays from 1 to 4 p.m.

Dormant and delayed dormant sprays will control insect pests and diseases such as overwintering scales, aphids and mites. These sprays are oil based and smother overwintering fungal spores, bacterial blights, insects, larvae and eggs. These insects cause leaf damage such as leaf curl and leave unsightly and misshapen fruit.

Dormant sprays are applied to a bare tree before the buds show any activity. This is usually in late winter when the day-time temps are in the 40s and the nights are above freezing. The right day to spray will vary depending on what part of North Central Washington you live.

Delayed dormant sprays are applied in late winter just as the buds begin to show the first green tissue when the daytime temperature is between 45 and 55 and no freezing at night.

Pre-bloom sprays are applied when the flower buds show color but before the flower opens. These sprays control hatching insect pests such as aphids, stink bugs, scale, peach twig borer, pear psylla, various feeding caterpillars and coryneum blight, brown rot and powdering mildew. Whew! That is quite a list isn’t it? So you can see why this spray application is necessary.

If you were not aware of all the problems associated with growing backyard fruit, you may want to decide not to have backyard fruit trees. Yes, the shade is nice. No, the insects and diseases are not. Lovely fruit is delicious.

Remember that no sprays are applied when your fruit tree is in bloom. You do not want to kill the pollinizers such as honeybees.

After the flower petals have fallen off and the young fruit is barely visible, it is time again to spray for powdery mildew and aphids, scale, mites and feeding caterpillars.

Within 17-21 days after full bloom, apples and pears need to be sprayed on a regular schedule to control for codling moth and pear psylla until the fruit is harvested. Cherry sprays to control cherry fruit fly and spotted winged drosophila start when the fruit turns from light green to yellow green and continues until all the fruit is ripe and removed from the tree.

Often, fruit trees have grown so large that they cannot be sprayed with a hose-end sprayer. In that case, commercial spraying is the option. The other option is to treat the tree with a chainsaw at the base.

A WSU Master Gardeners of Chelan County column appears weekly in The Wenatchee World. Bonnie Orr is one of four columnists featured.