Dollar spot is common on all types of lawns including bluegrass, tall fescue, and zoysia. Dollar spot results in the formation of small, circular, bleached patches in the lawn. Most spots are only a few inches in diameter, however under favorable conditions they may exceed six inches or coalesce into large irregular dead areas.
Grass blades on infected plants develop light yellow to tan lesions with reddish-brown borders. These symptoms are normally located in the middle of the leaf and extend across the blade.
The fungi which cause dollar spot can survive indefinitely in thatch and soil. In the presence of the right temperature and moisture on the foliage the fungi will start to grow. Dollar spot is most severe in late spring and early summer and again in early fall.
The presence of dollar spot often signals improper fertilization since the disease is most severe in nitrogen deficient lawns. Maintain adequate fertilization and avoid night or evening watering to reduce spread of the disease.
Fungicide applications are not recommended for control on home lawns as the disease has already spread before symptoms appear. Reseed in the fall or allow the turf to naturally fill in some areas.
For more information refer to the following K-State link: (link name: Dollar Spot in Home Lawns).