Problem: Slime Molds
These fungi feed on decaying organic matter in the soil. They do not feed on green plants. When the powdery covering is heavy, it may damage the grass by shading the blades from sunlight, causing them to turn yellow. Slime molds occur on dichondra, all turfgrasses, and some weeds. While slime molds are feeding on decaying organic matter in the soil, they are white, gray, or yellow slimy masses on the soil. When they are ready to reproduce, they extend up onto grass blades and form powdery balls containing spores. This phase of the life cycle is more noticeable than is the slimy mass phase.
In most cases control is not necessary. Although slime molds are unsightly, they do not permanently damage the lawn. Remove the molds from the grass by hosing with a strong stream of water or by sweeping the surface with a broom.