If you notice mushrooms growing in your lawn is a circle or an arc, you may be seeing signs of a disease known as Fairy Ring. Mushrooms are not the only indicator of Fairy Ring activity. Often times you may see a circle or arc of brighter green grass that range in diameter from 2 to 15 feet. Sometimes the rings may result in grass that appears dead or dying. There are about 60 different types of mushrooms that result in the development of Fairy Rings.
Fairy ring folklore is varied and quite extensive. The name Fairy Ring may have come about from the legend that fairies were dancing in a circle at night and used the mushrooms as tables from which they ate. In other countries, Fairy Rings were omens of misfortune or evil and were to be avoided at all costs. The largest Fairy Ring in the world is located in France. It is estimated to be 700 years old and is over 2,000 feet in diameter.
Dealing with Fairy Rings in a home lawn can be an arduous task. As the disease develops, it produces fungal strands called mycelium which grow in the soil or thatch. In the early stages, the mycelium will produce nitrogen, which may result in a darker green circle. As the disease progress, the mycelium can thicken and constrict water movement into the soil, resulting in dead or dying grass. One of the best ways to deal with Fairy Rings is to aerate the area to increase water penetration into the soil. The area will have to be aerated several times over several years to get control. The darker green circles can be “masked” with nitrogen fertilization to even out the color.
For the most part, Fairy rings are more of a nuisance than a major disease problem. Core Aeration is a good way to keep the disease in check, but requires that the lawn be aerated at least twice a year for the next three to four years. Aeration is one of the best things you can do to your lawn, so treating Fairy Ring will help your lawn improve as well