Proper soil pH and nutrient levels, especially phosphorus, in new lawns help to prevent or reduce the severity of this disease. Rust occurs on tall fescue and is seen more often in later summer on older plants. The symptoms of rust are small yellow spots on leaves with masses of yellow to rust colored microscopic spores in the center of the spots. Infected leaves may become yellow and die slowly. Most of the tall fescue plants will recover from the rust disease during favorable growing conditions in the fall.
Pythium blight can occur on tall fescue during long periods of hot-wet weather.
The turf appears to wilt in irregular patches and gray masses of fungus mycelium may be present on the dying grass. Low nitrogen levels, good soil drainage, infrequent irrigation and good air movement will help prevent Pythium blight. Fungicides may be needed to control this disease in highly maintained landscapes. Fairy rings cause various symptoms including dead, green, or a combination of dead and green rings in turf. The rings may be from a few to hundreds of feet in diameter.