We would like to bring attention to a wide spread problem of fungus outbreaks in the middle of summer on turf grass, primarily Brown Patch. This disease affects every cool season grass which includes bluegrass, ryegrass, and fescues which are most prone for infection. These three grasses happen to be the most dominant in our area.
Several factors contribute to this fungus developing:
- High humidity
- High temperatures at night (nighttime above 68 degrees)
- High amounts of nitrogen (this is somewhat inevitable with any fertilizer plan in place)
- Low wind speeds
- High irrigation/prolonged wetness on leaf blades
All of these factors come together between June and August when we hit our periods of extreme heat. We can be sure that we will start seeing symptoms if we have consecutive days of these conditions. Symptoms include large, irregular shaped circles in the turf. Upon closer inspection there may be a gray-purplish ring around the perimeter with individual leaf blades showing tan, brown, or red lesions.
More information can be found at:
http://www.extension.umn.edu/garden/yard-garden/lawns/turf-patch-diseases/