A balanced nitrogen fertility program in the fall will eliminate the need for fungicide. Red thread may occur on all cool season turfgrasses used for Midwestern lawns. It is generally a disease of spring and fall, with symptoms often disappearing during the heat of the summer. Outbreaks occur in turf stands where nitrogen fertility is at less than optimum levels. The disease may be spread by water or machinery moving over infected turf.
Patches enlarge as the fungus grows outward from the initial infection site.
The patches tend to have a pink cast. The threads are structures called sclerotia that enable the fungus to survive among turf debris in upper layers of soil. Symptoms can be confused with dollar spot at initial observation. However, the dollar spot pathogen does not produce the red sclerotia on leaf tips, and the red thread pathogen does not produce the bleached appearance of infected leaves nor the hourglass-shaped lesions characteristic of dollar spot infection. The information given herein is supplied with the understanding that no discrimination is intended and no endorsement by the Purdue University Cooperative Extension Service is implied.