Brown patch is often confused with burn spots or perhaps pet waste damage in lawns. In fact, the disease is caused by a species of fungus called Rhizoctonia.
Although the fungus most commonly effects cool season grasses and can be particularly harmful to ryegrass and tall fescue, it can also effect some warm season grasses like St. Augustine and Zoysia.
With the amount of rain that we have already had this season, combined with warm temps and high humidity, it is very common to see this fungus begin to take over. If not properly treated, brown patch can quickly spread and take over a lawn.
The disease will begin to appear in your lawn as a circular patch that is brown or yellow. Patches can be large or small and range anywhere from 6 inches wide to several feet in diameter. The fungus damages the plant and can be noticed on the blades of grass themselves. Looking closely, you may notice lesion type markings on the leaves.
Proper lawn maintenance help prevent brown patch. We recommend regular mowing, aeration, removing excessive thatch and proper irrigation. Of course, it can be hard to control the weather, so during periods of excessive rain or humidity, brown patch can still occur.
Here in the south in areas like Raleigh, NC, it is common for this lawn disease to occur. Our climate at times can receive heavy rainfall and during the summer months, nighttime temperatures regularly stay above 68°. Humidity and moisture are certainly increased risk factors for fungus to grow.
Fungicide treatment does not cure existing brown patch damage, but is very effective at preventing it from spreading. At Canopy, we regularly keep an eye out for brown patch in our customers’ lawns. We always try to review each case individually and treat with fungicide when necessary.