Fungi that don't attack grass directly but interfere with the roots' intake of water, oxygen, and nutrients. Look for a circular ring from a few inches to 50 feet in diameter, often with darker green grass inside and mushrooms around the edges. The disease generally can be ignored in home lawns. To control it, soak and feed the area with a garden root feeder. Remove thatch. Aerating or applying a wetting agent may help water penetrate. The only ways to eliminate the problem are to replace the infested sod or fumigate.
