The Master Gardener: Control fruit tree diseases with fungicide spray in fall

As fall deepens, the number of gardening tasks left to do gets smaller and smaller. Some, like sharpening tools for next year, can be skipped or postponed until spring without serious consequences. Not so with fall sprays for fruit trees. The common diseases of peaches, apricots, plums and cherries are best controlled with fall fungicide sprays.

Most insect problems (aphids on the leaves and worms in the fruit) are best treated in the early spring, so make a note of what bugs plagued your trees this year and be ready to deal with them next year.

Here are the diseases you should tackle this fall:

Apples: The cause of spotty leaves and rough scabby fruit is usually a fungus disease called apple scab. Fungicide sprays won’t be of use until spring, but the overwintering spores are lying in wait in the fallen leaves and fruit around your trees. Rake those up and get them out of the way to reduce the number of spores that will germinate next spring.

Peaches, apricots, plums and cherries: These fruit trees are all susceptible to diseases that cause red or brown spots in leaves and dieback of twigs and branches. Sometimes there are splits in the bark and sometimes there are brownish blobs of sap exuding from them. Bacterial canker and Coryneum blight are diseases that cause these symptoms. Their spores overwinter in the margins of these cankers and in the rough tissue around buds.

First, prune out the dead and dying branches and remove them from your orchard or garden. Then, as leaves begin to drop off, (and with any luck, before heavy rains start) spray trees with one of the many copper fungicides available in garden centers. By spraying as the leaves fall, you are protecting the tissue where next year’s buds are. Copper Fungicide, Kop-R-Spray, Microcop, Daconil, Immunox and Captan are all examples of copper fungicides, but there are others, too. Read all product labels and be sure the one you purchase is labeled for the kind of fruit tree you have and the diseases you are trying to control.

For more information on diseases and pests of fruit tree and other garden/farm plants, visit WSU Extension’s “Hortsense” Web page at http://pep.wsu.edu/hortsense or call your local Master Gardener Program.

This week in the garden

“Work compost into areas as you pull out annuals or transplant other plants. Your plants will thank you next spring.

“Finish removing old raspberry and blackberry canes and tying up the new ones. Keep the largest and strongest ones for next year. Top dress the cane bed with compost.

“Plant a layered bulb garden by digging a hole deep enough for daffodils and tulips and then adding smaller bulbs as you fill the hole with dirt. This will extend your bulb season and keep bulbs in one place.

“Aerate lawns before applying the last fertilizer application. The holes will channel fertilizer, compost and winter rains deeper into the soil.