I have seen and had calls on slime mold in lawns this week. With the high humidity we have had this week it has helped create a good environment to host this. Slime mold will show up in patches on your turfgrass and look like black spots in the yard. They are pin-head sized fruiting bodies on the blades of grass and usually in a irregular circle. It will not kill your grass but rather weaken the health.
Large numbers of pinhead-sized fruiting bodies may suddenly appear on grass blades and stems in circular to irregular patches 1-30 inches in diameter. Affected patches of grass do not normally die or turn yellow and signs of the fungi usually disappear within 1 to 2 weeks. These fungi normally reproduce in the same location each year. The fungi are not parasitic, but they may shade the individual grass leaves to the extent that leaves may be weakened by inefficient photosynthesis.
Conditions Favoring Disease:
Slime molds are favored by cool temperatures and continuous high humidity. An abundance of thatch favors slime molds by providing food directly in the form of organic matter.
# Remove slime mold by mowing.
# Remove using gardening tool or high pressure stream of water.
For more info visit University of Georgia Thomas County Extension Office or our website.