SEASON: Mid- to late summer.
APPEARANCE: Large, irregular circular areas, up to several feet in diameter, occur throughout the lawn. The patches usually have a brownish to gray discoloration with a water-soaked appearance around the edges. Normally, only the leaves and stems are attacked.
FAVORABLE CONDITIONS: High temperatures (75º to 95º F), heavy or dense thatch, high humidity, lush or weak growth from overfertilizing, and excessive moisture create perfect conditions for this disease to thrive in.
SUSCEPTIBLE GRASSES: It attacks Kentucky Blue, bentgrass, Bermuda grass, ryegrass, fescue, and zoysia grass.
RESISTANT VARIETIES: 'Manhattan II', and 'Pennant' perennial ryegrasses; 'Rebel II' and 'Wrangler' tall fescues.