All warm and cool season grasses.

Develops in late April through October. Favors high relative humidity and daytime temperatures over 80°F and nighttime at 60°F. Excess soil moisture, extended leaf wetness/or nitrogen fertilizer.

Grass killed in circular patches inches to feet across. In Bermuda, Centipede, Ryegrass; patches are brown. In St. Augustine; straw colored. Smoke rings present in Bentgrass. Webbing may be evident in the morning.

Correct water problem; don’t over fertilize. Use low amounts of nitrogen, moderate amounts of phosphorous and moderate to high amounts of potash. Avoid nitrogen when disease is active. Increase cut height. Increase air circulation. Minimize the amount of shade. Irrigate early in the day to allow foliage to dry. Improve drainage. Reduce thatch.  Remove dew early in the day.  Recommended fungicides may help prevent further infection while corrective cultural practices are taken.

All warm and cool season grasses. Tall Fescue, Bentgrass, Zoysia and Bermuda hybrids are susceptible

Dry soil conditions, extended leaf wetness and low nitrogen in the soil.

Circular straw-colored areas a few inches across, although spots may merge, resembling brown patch. Live blades may have straw-colored lesions along one edge. Lesion moves across blade causing tip to die back. Abundant white fungus may be present during severe disease development and may be visible in early morning.

Fertilize as needed; water adequately. Use adequate nitrogen, particularly in spring and early summer. Mow regularly. Irrigate early in the day to allow foliage to dry. Reduce thatch. Increase air circulation. Irrigate deeply and infrequently to avoid drought stress. Recommended fungicides may help prevent further infection while corrective cultural practices are taken.

Annual Bluegrass, Tall Fescue, Perennial Ryegrass and varieties of Bentgrass, Bermuda, Centipede, Zoysia and St. Augustine.

Excessive soil moisture. Some disease species favor temperatures between 32°F and 50°F and others thrive at 70°F and 90°F.

Small irregular spots may enlarge and appear dark and water soaked in early stages. White cottony webbing may be evident, in some species in early morning. Turfgrass affected dies rapidly, collapses and appears matted.

Control over watering and/or drainage problems. Apply optimum amounts of nitrogen, phosphorous and potassium. Reduce mowing frequency and use lightweight mower. Apply low amounts of nitrogen in the spring when roots are forming. Minimize shade. Reduce soil compaction using lightweight aerification equipment. Recommended fungicides may help prevent further infection while corrective cultural practices are taken.

Perennial Ryegrass, Tall Fescue and all varieties of Bentgrass, Bermuda, Zoysia and Centipede

Low potassium, extended leaf wetness and/or nitrogen levels in the soil. Disease favors temperatures between 40°F and 80°F. Occurs in areas which experience more than 10 hours of leaf wetness for several consecutive days. Favors high nitrogen and low mowing height. Can become severe in dry soils.

Small dark spots or streaks on grass blades and sheaths. Leaf spots are more numerous near collar area of leaf blade. Severely affected grass may become brown and thin.

Perform soil test. Reduce turf stress by using lightweight equipment. Increase air circulation to speed turf’s drying process. Avoid high application rates of water soluble nitrogen in the spring. Minimize shade. Irrigate turf deeply and infrequently as possible. Reduce thatch in early spring or fall for cool season turfgrasses and in the summer for warm season turgrasses. Recommended fungicides may help prevent further infection while corrective cultural practices are taken.

St. Augustine, Bermuda, Centipede, Bentgrass and various species of Fescue.

High humidity, warm temperatures, high nitrogen.

On St. Augustine first appears as small brown spots on leaves and stems. Spots quickly enlarge to inch and become bluish-gray in color and oval or elongated in shape. Mature lesions are tan to gray and have depressed centers with irregular margins that are purple to brown in color. A yellow border on lesion can also occur. Severely affected blades with and turn brown.

Avoid medium to high nitrogen levels during mid-summer. Irrigate deeply and infrequently to avoid water stress. Allow water to remain on leaves for only a short period. Reduce thatch by vertical cutting. Choose plants resistant to disease. Avoid using herbicides or growth regulators when disease is active. Recommended fungicides may help prevent further infection while corrective cultural practices are taken

Centipede and St. Augustine in south and coastal Georgia.

Presence of fungus and moist, warm weather.

Circular or semi-circular band of darker than usual green grass. Grass inside ring usually not as vigorous and may be declining. Grass may be dead inside of young rings; a band of dead grass in the middle may be seen in older rings. During rainy, moist conditions, a ring of mushrooms may appear.

Spike turf in the darker green areas using an aerator. Thoroughly saturate the area with water to leach fungal toxins further into soil and away from roots. Water and fertilize declining area inside ring appropriately to stimulate new growth. Reduce thatch by vertical cutting.
Recommended fungicides may help prevent further infection while corrective cultural practices are taken.

Bentgrass, St. Augustine, Bermuda and Centipede.  Bluegrasses and Fescue are rarely affected in Georgia.

Occurs in wet conditions and soils with high PH being most severe at 6.5 and above. Most severe on less fertile and sandy soils.

Causes wilted circular patches that are brown or bronze colored and measure several feet in diameter. Infected plants have dark-brown roots.

Use acidifying fertilizers. Apply moderate to high amounts of Phosphorous, potash and minor elements where nutrients are depleted from soil. Improve drainage. Reduce thatch. Recommended fungicides may help prevent further infection while corrective cultural practices are taken.

Bluegrass, Ryegrass, Bentgrass, Zoysia, Bermuda and Fescue

Light yellow flecks on the leaf blades and sheaths. Flecks enlarge, elongate and turn yellow in color. Infected areas raise above the epidermis and rupture, releasing yellowish-orange to reddish-brown spores

Occurs in early spring through mid-summer. Favors moist, low light areas. Favors temperatures between 65°F and 85°F. Severe infections occur on slow growing turf, particularly turf with low nitrogen levels and/or water stress.

Apply adequate levels of nitrogen. Reduce thatch. Remove clippings. Reduce shade and improve air circulation. Irrigate early in the day to allow foliage to dry. Water deeply and infrequently. Recommended fungicides may help prevent further infection while corrective cultural practices are taken.

No specific conditions, damage more evident during hot, dry periods

Attack root system, so above ground symptoms may include appearance of drought stress or nutrient deficiency. Root system may be stubby, coarse, maybe blackened somewhat.

Perform soil test. Fertilize if needed and water appropriately to keep turf as vigorous as possible. No nematicides for homeowner or landscaper available.  Limited availability for golf courses. Be aware of restrictions.