Summer Patch/Necrotic Ring Spot


Symptoms: From spring to early fall, lawns can be affected by one or more very similar patch or ring-type diseases. Circular rings or patches of injury may appear, and at times a tuft of grass may survive in the center of dead areas. This may create a frog eye appearance. Usually, the disease is most noticeable on sodded lawns. As the disease develops in summer, circular-like areas will turn a dark blue-green color and wilt in the heat of the day. Symptoms due to draught begin to show, and if the turf is not watered soon, wilted areas could die in a few days, or even within 24 hours.

Cause: The fungi that cause these diseases attack roots and crowns of grass plants during cool and wet periods, but damage does not become obvious until the turf becomes stressed due to hot dry weather. Symptoms of both necrotic ring spot and summer patch are most common in the summer, but necrotic ring spot symptoms sometimes persist into early fall.

Control: There are no simple treatments for complete control of summer patch diseases. Some fungicide treatments may help to suppress disease-causing organisms, but treatment must be accompanied by good cultural practices. Ideal cultural practices in established lawns include tall mowing, aeration, proper fertilization, and prevention of drought stress. Eliminating drought stress is very important, and turf must be watered quickly once wilted areas begin to occur.

Grass Carpet Lawn Service can suggest cultural practices and treatments that may help suppress patch diseases, but complete cure is not guaranteed. Please feel free to give us a call if you would like more information regarding summer patch.