Dollar spot is usually found on fine textured and close-cut turf. The disease produces small spots that are 2 to 6 inches in diameter in affected turf. Dollar spot usually occurs in late spring and throughout the fall during periods of warm humid days and cool nights.
Symptoms
Leaf spots are hour-glass shaped; they extend across the blade with bleached centers and brown, purple, or black borders. Early in the morning cottony fungal growth can be seen on infected blades. Bluegrass, ryegrass, and fine fescues are hosts, especially in poorly nourished turfs. Plants are rarely killed from this disease, primarily a leaf bright.
Cultural Control
Aeration or dethatching creates more airflow allowing the grass to dry faster. Also watering at the correct times and keeping a well-nourished lawn will help. Increase the strength of your lawn by implementing a fertilizer program.
Treatment
A fungicide treatment is recommended. Ask your local lawn and garden retailer for assistance.