Summer Patch on Turf Plant Pathology Summer Patch on Turf Lawns have been suffering this summer from a number of health problems. Summer patch symptoms include circular patches of straw-colored grass, up to a foot or more across, often with green grass in the center of the patch. The browning typically starts during July or August.
Summer patch is caused by a fungus that lives in the soil and attacks the roots.
It attacks roots during spring and fall, too, but symptoms are most often expressed in the summer months, when the lawn is stressed by heat and demands much water. Summer patch damage ranges from slight to severe. A few patches may appear and fade out in September. These spots may reappear during hot weather the following summer. In other situations, hundreds of straw-colored patches may mass together, leaving only scattered tufts of green grass.