Lawn Diseases

Slime Molds

Slime molds cover above-ground plants with a dusty-gray, black, or dirty yellow mass. When you look closely, you see small, round balls scattered over the plant. If you rub these balls between your fingers, a minute sooty-like powder covers them. This sooty-like powder is the spores of the fungus.

Slime molds normally live on the soil, where they feed on decaying organic matter. Slime molds do not feed on living plants. They use them for support during reproduction. They damage grass and other plants only by shading them from sunlight, causing the leaf blades to turn yellow. Slime molds occur in wet weather in spring, summer, and fall. They disappear rapidly as soon as it becomes dry.

Control: Control is usually not necessary. You can break up the masses by sweeping with a broom, spraying with a strong stream of water, or just dragging a hose over the affected area. In prolonged damp weather, you can apply any good contact turf fungicide such as chlorothalonil to affected areas.