Pest Alert: Large Patch

by | Nov 11, 2021 | Pest Alert

Large patch is a seasonal disease of warm-season grasses caused by the fungus Rhizoctonia solani. It typically occurs between November and May when daytime temperatures fall below 85 degrees. Symptoms begin as small, irregular, reddish-brown, brown, or straw-colored patches in the lawn. These areas rapidly expand. Where the pathogen is active, the outer edge of patches may have a distinct orange tint, while the middle section may appear straw-brown.

Large patch is less damaging than many other turf diseases because roots and stolons (runners) are not affected. Treatment will stop the disease from expanding and, if grass is actively growing, symptoms will disappear when new, green grass blades are formed. If the turf is not growing because of cool temperatures, symptoms will disappear with the spring growth flush.

If large patch is suspected, do not add additional water or fertilizer as this could make symptoms worse. Please contact our Customer Care Center at 1-800-481-0096 or submit a Customer Care Request online. An Agronomy Specialist will come out to confirm the diagnosis and apply the proper treatment.