June 2025
The disease most commonly occurs because of low fertility, drought, lack of sunlight, or other causes of stress.
While affected areas of grass appear to be dead, red thread doesn't kill the grass. The fungus that infects the turf lives in the thatch and is spread by water, wind, equipment and people. The pink growths that appear in the grass do not infect the crown or the roots of the plant, so although unsightly, the grass is not killed by the fungus.
Often times, an application of fertilizer will reduce the severity of red thread. Treating red thread with a fungicide is generally not necessary for home lawns but fungicides are a viable option for extreme cases or for those who find it aesthetically unpleasing.
Proper cultural practices to discourage red thread include:
- Maintain an adequate and complete fertilization program.
- Water deeply and infrequently to prevent moisture stress.
- Water in the morning to remove dew from the grass.
- Prune trees and shrubs to improve air circulation and increase light penetration.
- Keep mower blades sharp to minimize leaf wounding, which can enhance infection.
- Collect grass clippings when disease is active.
- Manage thatch, which can harbor the fungus.
- Overseed with resistant varieties of turf grass.
