Tiny Black Mold Growing in My Mulch

Identification

• Slime molds develop on cool and warm season turfgrass. Although it is unsightly, slime mold does not usually damage grass. Slime mold appears in humid climates and is most common after frequent periods of rain. The black spores associated with slime mold can also develop on sidewalks and driveways, as well as mulch, grass and plants.

Effects

• Tiny black fruiting bodies signal the existence of slime mold on mulch. This mold often begins as bright orange or yellow blobs on mulch surfaces. Slime mold produces tiny, black spores which dry and blow away on the wind. This type of mold can range from a few inches to several feet in diameter.

Control

• Control is not necessary for slime mold because it does not harm plants and grass. However, homeowners who wish to improve the appearance of their yard, can rake slime mold or wash it away with water. However, using water on slime mold is only recommended if the weather is dry, since moisture favors fungal growth.