What are the green circular areas on my lawn? Is it a disease? What can I do about it? I&8217;ve heard lots of similar questions and complaints this summer about the green rings on some of the lawns in the Miss-Lou.

You may wonder what causes these green rings. The answer plain and simple is mushrooms. The common name used to describe the condition is &8220;fairy rings.&8221; The name was given to the circular regions in the Middle Ages because people thought the areas had supernatural powers due to fairies that danced in circles where the rings appeared.

Over 61 different fungi have been identified that cause fairy ring symptoms although each individual ring consists of only one type of fungi. I am not a mushroomologist so it would be hard for me to tell one type from another.

The rings begin as a single spore that germinates in the thatch layer of the lawn. The resulting mycelium slowly grows out radially each year, eventually creating a ring. When the conditions are favorable, the fungi will produce mushrooms on the outer edge of the circles.

Fairy rings can become rather large. The largest one identified to date by DNA testing is in Alberta, Canada &045;&045; the ring is 2,600 feet in diameter and estimated to be between 1,000 to 1,200 years old. So, in fairy ring years, yours are most likely just babies.

Fairy rings are not technically a disease, because they are not parasitic to turfgrass. The organisms are obligate saprophytes that only live on dead and decaying organic matter. On a lawn, that would mostly be the thatch. The greening effect is the result of a release of nitrogen as the fungi decompose the thatch. The process is actually healthy for the lawn. The biggest problem from a lawn management standpoint is that the fungi growth results in a hydrophobic soil condition that makes the area drought prone.

What can be done about fairy rings? Unfortunately &045;&045; not much. Increased core aerification can help by reducing the thatch that the fungi live on. Some fungicides may suppress the effects of the rings but the results are sporadic at best. Excavation of the infected soil works but would obviously be very disruptive to the landscape. I realize that many of you find it hard to believe that not much can be done to alleviate the fairy ring problem &045;&045; just as I can&8217;t believe that doctors can&8217;t cure the common cold.

Many legends surround fairy rings. In France, farmers are afraid to till an area that has a fairy ring, fearing crop failure as a result. In England, people believe it is good luck to build a house on a site with a fairy ring. In Ireland, golfers believe that you are more likely to sink a putt if the hole is cut within a fairy ring.

Fairy rings have been around for a long time and will no doubt be here for your grandchildren. In the meantime, if you happen to see any fairies dancing on your lawn, please let me know about them immediately!

Traci Maier

writes a weekly column about gardening in the Miss-Lou. She can be reached by e-mail at

ratmaier@bellsouth.net