The telltale signs of these soil-inhabiting fungi are toadstools, mushrooms, or puffballs of various shapes and sizes. When the mushrooms are absent, fairy rings look like circular areas of dead or dying grass, which often have a dark green border. These fungi feed on old roots, stumps, and thatch. Fairy ring fungi are not plant parasites, but they can cause drought stress in lawn grasses because their fungal strands or mycelia make the soil repel water.
Fairy rings are difficult to control.
You can be patient and allow the fairy rings to disappear over time. Watering the ring to saturate the soil for several hours and over several days may help. Finally, you can replace the infested soil occupied by the fairy ring with clean soil.