Hort Q&A: How to control pests, disease

Carla Smith, horticulture educator
Pottawatomie County Extension Service

I have had problems with pests and disease, what do you recommend to help with that?

One of our best defenses to common pest problems in the garden and landscape is plants with natural resistance. By selecting varieties of plant species, or species that are inherently resistant to common pest problems, the use of pesticides needed to keep our plants looking good can be reduced.

When buying seeds or plants, try to choose those with built-in resistance to diseases, insects, and nematodes. Sources for this information include OSU Extension Fact Sheets, seed catalogs, and plant and seed packages. It may be better to forego some production capability in favor of the increased pest resistance, if you must make such a choice.

During the growing season, stressed plants can lose their resistance to pests, so be sure the crop has the water and nutrients it needs. When shopping for seeds and plants, check the labels for indications of pest resistance. For example, many garden phlox and crapemyrtles are susceptible to powdery mildew fungal disease; however, several varieties are available that are resistant to powdery mildew. When purchasing vegetables, check labels or packaging for abbreviations like these, used to designate various types of pest resistance or tolerance:

A—Alternaria stem canker N—nematode

ALS—angular leaf spot NCLB—northern corn leaf blight

ANTH—anthracnose PM—powdery mildew

CMV—cucumber mosaic virus SCLB—southern corn leaf blight

DM—downey mildew St—Stemphylium (gray leaf spot)

F—Fusarium (race 1) SW—Stewart’s wilt

FF—Fusarium (races 1 & 2) TMV—tobacco mosaic virus

L—leafspot V—Verticillium

MDM—maize dwarf mosaic

Another tool we use to prevent and reduce disease is to rotate what we plant. We may all have our favorite go-to plant for a certain space, but changing it up can provide a new color, a fresh look, or a new flavor to experience. Whether edible or ornamental, if we have a known pest issue, simply planting something different can help resolve the problem.

If you would like to try something new, check out the Multi-County Master Gardeners Plant Sale on May 8 at our office parking lot, 9 a.m. to 1 p.m., or when we run out. Please use the parking along Acme Road as our parking area will be used to space out the people traffic for the plant sale. Help us keep everyone safe by respecting distance and wearing masks! See our website event section or our Facebook page for details: Pottawatomie County OSU Extension.

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