Manage plant diseases naturally


Damp Northwest weather is hard on some varieties of plants, but there are easy ways to prevent diseases like black spot and powdery mildew without hazardous chemicals.

Build healthy soil. It grows healthy plants. Healthy plants are less likely to be harmed by diseases. Compost and organic fertilizer will enrich your soil with nutrients, help hold water, loosen clay and feed beneficial soil life.

Choose disease-resistant plants. Opt for native plants, or non-natives adapted to our wet-winter, dry-summer climate.

Avoid the few natives prone to problems in garden settings. Try a dogwood resistant to anthracnose or a maple resistant to verticillium in the place of susceptible native varieties.

Give roses lots of sun and air. Keep the leaves dry to discourage most diseases. Plant them where they’ll get six hours of sun a day. Prune to improve air circulation and clean up diseased leaves.

Treat diseases and insects separately. 2 in 1 products treat problems you may not have.

Use pesticides as a last resort. Many fungicides contain ingredients that are hazardous, but there are products available with safer ingredients like sulfur, jojoba oil, or potassium bicarbonate.

If you choose to use pesticides, pick a safer product using the brand-name product rankings in the Grow Smart, Grow Safe product tables.