DESCRIPTION: Fairy rings are reported to be caused by many (60) different soil-inhabiting fungi. These fungi may cause the development of rings or arcs of deep green grass. The dark green circles are the result of fungi colonizing the soil, leaf litter or thatch. The break down of organic matter by fungal activity releases nitrogen. This stimulates the grass on the outside of the ring, causing it to grow taller and darker than surrounding grass.

The band of stimulated grass is often associated with the fruiting bodies of the fungi. Mushrooms typically grow in the ring, are sometimes poisonous and are best picked and disposed of if young children frequent the area. Removing these fruiting bodies does not weaken the fungus.

LIFE CYCLE:  Fairy rings start from a piece of mycelium or spore. The uniform outward growth of the fungus results in the development of rings. Changing soil types, the fungus involved, condition of the turf, abundance and type of organic matter and obstructions all affect this radial growth. Fairy rings encountering each other in their development will typically produce a scalloped effect of stimulated or dead grass.

CONTROLS:

Cultural:  Turf subjected to extreme drought stress is more susceptible to problems from fairy ring. Top dress ring with humus builders (finished compost).  Fertilize and water area well.  Encourage water percolation by plunging a garden fork into the soil  five or six inches deep around the ring and watering well.  You may also remove the soil to a depth of one foot and wide enough to extend at least two feet on either side of the fairy ring.  Replace this soil with non-infected soil or finished compost and reseed or lay sod.  Fairy Rings does not destroy turf so it can also be ignored.<br>

Chemical: None available.  The application of fungicides is not a recommended control option.   The use of pesticides may increase the incidence of fairy rings by destroying saprophytic bacteria and fungi which compete with the fairy ring fungi.