Red Thread

Grasses most commonly affected: Kentucky bluegrass, fescue, perennial ryegrass.

What is Red Thread?

Red thread (Laetisaria Fuciformis) is a tall reddish “thread” that grows around the grass blade. Red Thread grows on top of grass as a host instead of killing it.  Red Thread prefers cool conditions and occurs in Spring and Fall.  Turf that isn’t receiving the proper amount of nutrition is more susceptible to red thread.

Red Thread Signs and Symptoms

Red Thread creates small patches of reddish tinted grass that from a distance may make the grass appear dead.  These patches are often confused with dollar spots and other lawn diseases.  Upon close inspection it is easy to see the red thread. A pink fluffy material, mycelium, can be found on the bottom of the infected grass blades.

Red Thread Prevention

Nitrogen-based fertilizers can help to control red thread. It is often associated with low nitrogen conditions, a moderate fertilization program will help to mitigate red thread. Water that sits on the leaf blades overnight will not be absorbed into the lawn and can cause a variety of lawn diseases, red thread included. For this reason Velvet Green recommends deep and infrequent watering every other day or at least 3 times a week. Early morning (4am - 6am) is best to limit evaporation from the sun. Lawn typically need 1-2 inches of water a week depending on weather conditions.

Although red thread is not aesthetically pleasing to the eye, a treatment is not always necessary. The Disease can often be eradicated through regular lawn maintenance.

Fertilizer programs that Velvet Green offers help to prevent and mitigate red thread through moderate nitrogen and beneficial microorganisms. Good cultural practices such as proper watering, mowing height (3-4 inches), sharpened mower blades, reducing thatch and compacation (aeration), and reducing leaf wetness when possible. Amendments offered by Velvet Green based on the results of soil testing can improve soil structure thus further helping to mitigate red thread.