Red thread is a disease of slow growing turf. Red thread is easily recognized by the red to coral-pink fungal strands (stromata) produced on leaf blades and sheaths. When turf is wet, the fungal stroma looks gelatinous and fleshy. As the grass dries, the stroma also dries and becomes thin and thread-like. Infected turf often appears to be suffering from lack of water, often times symptoms resemble dollar spot. Under close examination of the grass blades reveals red to coral-pink stromata. Under conditions of high humidity, pink cottony flocks of arthroconidia can be seen in the patches.
Red thread occurs is favored by high humidity at temperatures between 60°-90° F (15.5° and 32° C). Cool, drizzly days of spring and fall are ideal for the development, and the disease spreads from plant to plant by growth of the stromata. These can be spread by wind, and mechanical equipment.