Garden Mastery Tips
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January/February 2007 |
Dormant Care of Fruit Trees
The fruit is picked and stored, the air is crisp, and your thoughts are turning to winter hibernation. Don't get too attached to your couch, however, because one of the most important times to care for your fruit trees is during their dormant period. Follow this schedule to ensure healthier trees next year.
Fall Chores
- After the crop is harvested, but while the leaves are still on the tree, spray thoroughly with a copper fungicide. This will guard against anthracnose and nectria canker in apples and pears, coryneum blight and bacterial canker in peaches, plums, and cherries, as well as moss and lichen growth.
- Before the fall rains start in earnest, spread lime around the trees. Fruit trees prefer a neutral pH (6.5 to 7.0). In the Pacific Northwest, our soil is generally more acidic so a yearly application of lime is beneficial.
- Remove fallen fruit and leaves. Many insect larvae and disease spores will overwinter in the debris. Do not compost the debris – burn it or throw it out with the trash.
- If the trunks of your fruit trees split on the south or west side of the tree, they are suffering from winter sunburn. If a leafless tree is suddenly subjected to bright sunlight after a very cold period, the sap will swell and split the bark. This will provide an opportunity for boring insects to invade. To avoid sunburn, paint the trunks with interior white latex paint or wrap the trunks with a tree wrap available in nurseries and mail order catalogs.
- Small rodents such as mice or rabbits will gnaw the bark around the base of a fruit tree during the winter when there is little else to eat. Protect the trunks with chicken wire or hardware cloth at least 18 inches high. You can also purchase tree protectors for this purpose.
Winter Chores
- In late December and early January (at least by January 15), spray peach trees with copper or lime sulfur for peach leaf curl. Three applications are required about three weeks apart to get full protection.
- Spray all fruit trees with lime sulfur and horticultural oil once to control blister mites, scale, pear psylla, moss and lichens. This application can count as one of the peach leaf curl sprays.
- Prune for air circulation, sun penetration, fruit production, and to keep the trees a manageable size. For information on pruning consult the Pacific Northwest Cooperative Extension Publication No. 400, April 2003, Training & Pruning Your Home Orchard, available online at http://cru84.cahe.wsu.edu/cgi-bin/pubs/PNW0400.html.
Early Spring Chores
- During the ‘Delayed Dormant’ period, just when the buds are beginning to swell but before any new growth, spray all fruit trees one more time with horticultural oil. This will kill scale, aphid, and mite larvae.
- If you have not had good pollination, consider purchasing orchard mason bees. Build and mount bee houses near your fruit trees for a continuing supply of these wonderful pollinators.
Now it is time to sit back and watch all your fruit grow, at least until it is time to start the spring spray regimen.
NOTE: Use and store chemicals with care. Follow all label precautions to protect yourself and others around you.
Resources
Brickell, C., The American Horticultural Society Pruning & Training. New York: DK Publishing, 1996.
WSU Cooperative Extension Service, EB0918 Disease and Insect Spray Schedule for Home Orchard Peaches, Nectarines, Apricots, Plums, Cherries, and Flowering Plums.
WSU Cooperative Extension Service, EB0846 Disease and Insect Spray Schedule for Home Orchard Apples and Pears.