I suspect the problem is a fungal disease of turf that we call brown patch. Brown patch, caused by the fungus Rhizoctonia is problematic as we get into very warm weather with warm temperatures overnight. We see tufts of fungal growth on blades in the morning. Symptoms include irregular circular patches that are brown or tan in color. Individual lesions on blades are tan with a darker border. Fescue is very susceptible, although there are a few resistant varieties available. Avoid water late in the day, which can be difficult with afternoon thunderstorms. Do not overwater. Avoid high nitrogen fertilizer after early spring applications. Rhizoctonia will not kill the crown and roots, but can cause severe dieback of foliage. The turf should come back when conditions improve for growth of cool season turf grasses. Preventative fungicide applications may be necessary on high value sites, applied by professionals.
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