What are Fairy Rings?
Fairy rings, also known as fairy circle, elf circle, elf ring or pixie ring, are naturally occurring arcs of mushrooms in grassed areas or forests. They can be incomplete or complete circles and can grow to be over 30 feet in diameter.
There are three types of fairy ring found on lawns, those with a darker green flush of growth, a zone of dying grass and mushrooms, those with only a darkened green ring and mushrooms, and those with only mushrooms.
How to treat fairy ring?
Fairy rings do not cause widespread damage and are very hard to get rid of so they are most often just left alone. Increased fertilizer has been used to match the surrounding turf to the darkened green ring. Fungicides have been implemented but with limited success depending on the species of mushroom present.
Manually digging out the fairy ring has been done but the spores run wide and deep and must be dug out to a depth and width of up to four feet.
In European folklore fairy rings were thought to indicate the location of gateways into elfin kingdoms, or places where elves gather and dance. Maybe they should be left alone just in case.