Released: June 27, 2001

Fairy Rings Look Magical, But Can Kill Grass

MANHATTAN, Kan. -- Fairy rings are the stuff of folklore and ancient tales. They’re also a real problem in lawns -- especially in years like 2001, when many homeowners got through June without ever having to turn on a sprinkler.

"Basically, fairy rings are a type of mushroom growth that develops in an arc-like or circular pattern," said Ned Tisserat, Kansas State University plant pathologist. "The fungus forms a dense mat of interwoven filaments that makes organic matter decompose. This decomposition, in turn, releases nitrate -- a fertilizer. And the nitrate stimulates the turf on the outside of the ring, forming a margin of dark green."

The result may look like magic, but it can lead to serious problems. The thick fungal mat won’t allow water to penetrate to grass roots. In some cases, the fungus also releases a toxic byproduct that can directly kill the turf within a ring.

"At that point, lawn owners will find they have no best solution," Tisserat said.

Their choices will include:

* Hire a lawn care company that employs a certified pesticide applicator. Get the area drenched (sometimes repeatedly) with a fungicide such as Prostar or Heritage. That may help reduce the symptoms.

* On both sides of the ring, create a 1-foot wide trench that’s 6-12 inches deep. Remove the soil and replace it with soil that’s not infested with the fungus. Sometimes that will eliminate a ring.

* Mask the symptoms by fertilizing the rest of the lawn, so it’s as dark green as the ring. Be warned, however, that this will tend to promote other lawn problems.

Tisserat is the turfgrass disease specialist for K-State Research and Extension.

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K-State Research and Extension is a short name for the Kansas State University Agricultural Experiment Station and Cooperative Extension Service, a program designed to generate and distribute useful knowledge for the well-being of Kansans. Supported by county, state, federal and private funds, the program has county Extension offices, experiment fields, area Extension offices and regional research centers statewide. Its headquarters is on the K-State campus, Manhattan.

Story by:
Kathleen Ward, Communications Specialist
kward@oznet.ksu.edu
K-State Research& Extension News