Fairy Ring

During the spring or summer, a circle or arc of stimulated grass or of mushrooms may appear in lawns. These are turf abnormalities called fairy rings. These rings of lush growth in the lawn are caused by the release of nutrients, in particular nitrogen, from the activity of the fungus living on organic matter in the soil. These causal organisms are mushroom fungi. Symptoms: There are three kinds of fairy rings. One type has no mushrooms; stimulated grass growth reveals the activity of these fungi in soil. Another type contains a ring of mushrooms as well as a ring of stimulated grass growth. A third type contains only a ring of mushrooms, with no evidence of unusual grass growth. Fairy rings usually do not present a lethal threat to turf grass, but sometimes a ring of dead grass occurs in addition to the ring of stimulated grass growth. Death in the ring is due to the interference of normal penetration of water by the dense mat of fungus in the soil, toxic substances given off by the fungus in the soil, and possibly direct effects of the fungi on the grass plants. Fairy rings normally reoccur each year, and their diameter slowly increases overtime. Disease Cycle: Small rings appear as the initial symptoms of the infection. The rings become larger each year as the fungus grows in a radial pattern. Rings can increase in size annually and can become quite large after years of infections. Management: If the fairy ring consists only of mushrooms, with no stimulated grass growth, simply kick over or mow the mushrooms. As serious injury to the turf grass does not occur often with fairy rings, the most practical method of dealing with them in lawns is through a cosmetic approach. Disguise the symptoms by providing adequate water deep into the root zone, and by applying moderate rates of fertilizers. This will increase the vigor of the surrounding grass to the level more like that of the grass in the fairy ring. Excessive application of water or fertilizer should be avoided as either may contribute to other turf diseases or stimulate fairy ring development. More frequent mowing may make the difference in height between grass of the fairy ring and adjacent grass less conspicuous.

Lawn mushrooms in a circle around the perimeter of the fairy ring.

Dark Green Circles surrounding lighter green grass.