Slime molds are more of a curiosity than a threat to turf. These organisms are not parasites. They use plants for support and really only cause inhury if they smother the plant surface. Yellowing of leaf tissue may result. Slime molds are fungi that grow on organic matter and during wet weather "ooze" up onto foliage. This growth may first appear black (or some other color) and slimy, but eventually turn to a powdery substance (usually white, grayish-pink, or gray).
Slime molds usually reappear in the same area year after year, and last one to two weeks. Dormant periods in the life cycle of a slime mold are spent as spores in the soil and in the thatch. During warm rains or heavy watering, the spores absorb moisture until their walls crack open and release the swarming-type spores that ooze onto the foliage.
Control measures are not necessary, but if desired, are relatively simple. Slime molds can be removed by vigorous raking, brushing, mowing, or hosing down with a fast stream of water. Slime molds will disappear with changing weather conditions.
This article originally appeared in the July 15, 1994 issue, p. 113.