Brown Patch is a fungus that normally occurs during the mid-summer months, and appropriate to its name, results in the formation of unsightly circular patches of brown, blighted turf. This fungal disease is capable of killing the turf during extended periods of hot, humid weather.
Disease development is favored by nighttime temperatures above 60°F and by a high relative humidity and/or a thin film of moisture on the leaf surface. Brown Patch development can be very rapid; large blighted areas may develop within a 24 to 48 hour period. In light attacks, only the leaves will be affected and the turf recovers within two to three weeks. However, when conditions are favorable for the disease to persist, the crowns or roots may also be killed.
A fungicide application should be applied to prevent spreading of the disease. Our preventative program provides multiple applications, every 21 to 28 days, while weather conditions favor the disease. Do not irrigate lawns in late afternoon or evening if possible, this extends the number of hours the leaves remain wet and increases the likelihood of Brown Patch development. Irrigation after midnight to mid-morning is preferable, these are the hours the turf would normally be wet from dew. Irrigation in these early morning hours does not extend the leaf wetness period and allows the leaves to dry throughout the day. A light fertilization after a Brown patch epidemic may speed turfgrass recovery.
On some lawns, the disease may appear as rough circular patches that range in size from a few inches to several feet in diameter. The turf initially develops a dark purple-green color similar to that associated with drought stress, but the damaged areas quickly fade to light tan or brown. The leaves of the turfgrass plant are affected first, causing the formation of irregular, water-soaked spots. The spots may be bordered by a dark brown margin.
A more common symptom on newer Tall Fescue varieties is a uniform blighting without the formation of distinct, circular patches. Diseased lawns exhibit a droughty or wilted appearance even though sufficient soil moisture is present. Brown spots on the lawn can be caused by several different problems; dull mower blades, white grub damage and even pet urine. If you suspect that you have a turfgrass disease, please contact our office immediately so we may come and accurately diagnose the problem.