Red Thread Fungus in Lawns

Identification

• Red thread is a fungal disease most often seen in fescue and perennial ryegrass, according to North Dakota State University. Temperatures ranging from 68 to 75 degrees Fahrenheit are optimal for the development of this disease. Lawns low in nitrogen are most susceptible to red thread development.

Symptoms

• The symptoms associated with red thread in grass include areas that appear bleached out and water-soaked or greasy areas on lawn grass which turn light tan or brown over time. When wet weather sets in, these areas develop a slimy pink fungus which turns into red thready strands on grass blades.

Control

• Control of red thread in lawn grass is best accomplished with cultural practices. Applying a nitrogen-rich fertilizer during spring and fall months is key to preventing red thread. Watering your lawn frequently is essential to healthy grass, and avoid using fungicides on your lawn.