Turf Circles Made by Fungus

Types

• Fairy rings are a common cause of turf circles in lawn grass. This fungus affects both cool and warm season grasses and is most common in grass under environmental stress. Summer patch is another fungus that causes turf circles in grass. This disease is caused by the fungus Magnaporthe poae and usually occurs in the summer months. Brown patch causes circular spots on grass and is caused by the fungus known as Rhizoctonia solani.

Symptoms

• According to the Missouri Botanical Garden, the symptoms associated with fairy rings include circles in grass that are dark in color, and the grass inside the ring often wilts and dies. Mushrooms are often visible at the edges of the fairy ring. Summer patch symptoms include yellow patches in grass, thinning grass in patches and bronzing of grass. Eventually, all of the grass inside the patch dies. Brown patch causes circles in grass, which appear water-soaked and turn dark brown. Smoke rings are often visible when the grass is wet.

Control

• Avoid excessive watering in grass with turf circles caused by fungus, as this worsens the disease. Applying fungicides to grass is often beneficial in the treatment of fungal diseases.