Light green patches that spread, turn reddish brown and then die. Caused by a soil borne fungus, often in combination with other pathogenic fungi. Primarily attacks Kentucky bluegrass.
Usually occurs in hot, dry weather. Begins as a small spot, then grows until it kills the grass.
Do not over fertilize and maintain a good watering schedule. However, once symptoms are noticed, it's usually too late to control the disease for the current season.
Apply a Fungicide the following spring after an attack. Water regularly to keep the soil evenly moist (not wet, especially during extended dry periods).