The Ohio State University

Home LandscapeNotes In the last several days people have been asking about lawns that are black! There are also questions about what is causing black material getting on mowers, shoes, kids legs and pets. The culprit is saprophytic mold feeding on drought damaged grass leaf tissue. In these cases the lawns have been under dry conditions and much of the leaf blades have gone dormant and dead. All this dead plant tissue is excellent food for these saprophytic molds. Under these conditions and with abundant food, once a lawn receives rain or is watered abundant fungi (molds) grow on the dead organic material (leaves) and produce massive amounts of spores resulting in the black material in the lawn. The fungi and spores cover the turf and the can easily be dislodged and get on shoes, lawn equipment etc.

Anyone mowing lawns with these molds on the grass can expect to get dirty. With rain and cooler temperatures, the turf should come out of dormancy. In most cases the crown of the turfgrass plant is alive which is where new leaves develop and grow and the lawn should recover. If lawns are fine or there are dead areas seeding would be recommended. Fall is the time to fertilize turf to recover form summer damage. I there is one ideal time to fertilize a cool-season lawn now is the time.

Photograph by Tim Fine, OSU Extension, Miami County.

Posted by Joseph Rimelspach