Black or Sooty Mold in Turf

Black fungus on the grass can be caused by several different types of fungi: Sooty mold grows on honeydew from aphids, Slime mold, brown patch disease and gray leaf spot. Slime mold has a black, powdery appearance that moves up the stem from the base. Brown patch causes yellow to reddish-brown spots in the lawn, and a black rotten appearance where the stem meets the ground. Gray leaf spot turns the blades yellow with an edge of black.