Brown patch appears as roughly circular patches that are brown, tan, or yellow in color and range from 6” to several feet in diameter. Lesions are evident on the leaves that are tan in color and irregular in shape. When the leaves are wet or humidity is high, small amounts of gray cottony growth may be seen. Brown patch is most severe during extended periods of hot and humid weather (June to September). Poor soil drainage, lack of air movement, shade, cloudy weather, dew, over-watering and watering in the late afternoon, favor prolonged leaf wetness and increase disease severity.
Avoiding prolonged periods of leaf wetness will drastically reduce the severity of brown patch. Proper irrigation timing is needed to balance these factors. The lawn should be irrigated early in the morning, between 4am-7am with 1” of water, once a week. Avoid excess nitrogen as it can worsen the problem. Mowing height should be at least 3” and a regular fertilization schedule is crucial to give your lawn the nutrients it needs to bounce back.