Garden Q&A: Sidestep fungus, pests in orchard |

Garden Q&A: Sidestep fungus, pests in orchard

Jessica Walliser
Fruit trees need a good fall clean-up to prevent fungal diseases

Question: We moved into a house with a couple of pear and apple trees in the backyard. Though I’ve grown vegetables for years, this is the first time I’ll be growing fruit trees. Is there something I need to do before the winter arrives?

Answer: Start your foray into fruit growing with a good fall cleanup. Though it may not seem important, picking up all of the fallen fruit is a very important step in fruit tree management. Fruit left lying beneath the tree may provide a safe winter haven for certain insect pests. Pick it up and compost it as far from the trees as possible.

Fallen leaves also may contain a variety of fungal diseases. Rake up the leaves and compost them with a mixture of other ingredients.

You’ll also want to pluck off any grey, shriveled fruit still clinging to the branches (they’re called “mummies”), as this moldy fruit holds millions of fungal spores. These mummified fruits should be tossed into the garbage or burned, as most home compost piles don’t heat to a high enough temperature to kill the spores.

The pruning of fruit trees is best done in late winter. Proper pruning is truly an art best learned from the pros, not from a book. Contact a local orchard and find out if and when they’ll be hosting a hands-on pruning workshop. They usually take place in late February or early March.

You won’t need to begin an organic spray regimen until late winter, when the bare branches should be sprayed with a dormant oil. This product “smothers” overwintering insect pests and their eggs, and may help reduce fungal issues as well.

You’ll also want to purchase a few other products for your organic arsenal. Kaolin clay products (one brand name is Surround) coat the developing fruit with a white clay dusting that discourages pests; Bacillus subtilis-based fungicides are useful to help prevent fungal diseases; and red, sticky sphere-traps will help cut down on apple maggots.

All of these products are most functional when applied according to an appropriate schedule. You can find a schedule in the book “Grow Organic” (written by myself and co-author Doug Oster, available via and bookstores) or via the Penn State Extension Service’s publication “Fruit Production for the Home Gardener.” To order this guide, contact the extension service’s Publication Distribution Center at 814-865-6713.

And, though you don’t grow them, stone fruits like peaches, apricots and plums should be examined each autumn for signs of peach tree borer. Look for tiny holes in the trunk with bits of sawdust-like frass and sap coming out. If you find any holes, stick a straightened paperclip into the hole to crush the borer sheltering inside.

Horticulturist Jessica Walliser co-hosts “The Organic Gardeners” at 7 a.m. Sundays on KDKA Radio. She is the author of several gardening books, including “Attracting Beneficial Bugs to Your Garden: A Natural Approach to Pest Control” and “Good Bug, Bad Bug.” Her website is

Send your gardening or landscaping questions to [email protected] or The Good Earth, 503 Martindale St., 3rd Floor, D.L. Clark Building, Pittsburgh, PA 15212.

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