Problems With Brown Spots on a Lawn
- The disease known as brown patch occurs during the hot summer months, while yellow patch typically appears during cool, wet periods. Dollar spot also causes brown spots in the lawn.
- These fungal diseases cause similar symptoms, but often occur under different conditions or at different times of the year, aiding somewhat in identification. Brown patch causes brown circular patches 1 to 3 feet in diameter. Yellow patch often appears in newly laid sod or areas with thatch or heavy soils, according to North Dakota State University. Dollar spot creates 2- to 6-inch blotches or circular patterns, with the size varying depending on the grass species. It most commonly affects poorly maintained, unfertilized lawns.
- Avoid nitrogen application prior to hot weather and de-thatch regularly to reduce the occurrence of fungal diseases. Use fungicides to treat outbreaks. Keep lawns well maintained, including watering and fertilizing as suggested for your grass species. These measures keep lawns strong and healthy, reducing plant stress and the chance for disease development.
- Other possible causes of brown patches in the lawn include excess nitrogen from pet urine or excessive fertilization. In the spring, brown patches may appear in areas damaged by salt near roads, sidewalks and driveways. Water to dilute salt or nitrogen levels. Most areas recover with time, but consider reseeding large affected areas, suggests Texas A&M University Extension.