Mushrooms Invading Your Lawn?They’re Fairy Rings

Oct 3

Written By Columbia Community Connection

Story and photos by Dana Greyson

What Are Fairy Rings?

A pearly-looking necklace of mushrooms surrounds the trunk of my neighbor’s big leaf maple tree. His luxurious emerald-green lawn provides the perfect contrast for this phenomenon, known as a “fairy ring.” It’s prompted by cool, damp weather.

Fairy Ring Mythology

Per The Almanac*, according to myth, “fairy rings were created by elves or fairies dancing beneath the Full Moon. When the merry dancers grew weary, they used the toadstools as seats to rest on or as tables for feasting.”

*The Almanac (www.almanac.com/magic-fairy-rings-what-they-are-and-how- they-form) lists many more cultural musings about fairy rings; check it out if that’s your thing.

Are Fairy Rings a Problem?

Personally, I find fairy rings charming—perhaps because they’re not in my yard.

“What can I put on it to get rid of it?” asks my less-charmed neighbor, Lord of the Ring.

Fairy rings, mystical as they may sound, are a relatively common problem, especially where there are sandy soils—which tend to be infertile—and drought stress.

The good news is fairy rings can disappear as easily as they appear and can be helpful to trees and in cycling nutrients into the soil. While the fairy rings will continue to spread over time if not addressed, they don’t do much harm. However, they can block water penetration, make it easier for weeds to invade where the grass is struggling and many homeowners don’t like the way they look.

How to Get Rid of Fairy Rings

Mowing the lawn will temporarily remove the fairy rings, but until their root cause is addressed, they will return and expand. For a home lawn, general good lawn care—proper water, fertilizing and sufficient sunlight might take care of the problem. My neighbor’s lawn care checks all those boxes, though his maple does cast a fair bit of shade. Alas, what seems like the easier and thus often preferred quick-fix “what can I put on it?” solution—fungicide—is not recommended in this case for most home and commercial lawns.

These more challenging approaches could be what it will take for the lawn to fully eradicate fairy ring return

Aerate the soil for better water penetration.
Remove thatch if more than ½ inch builds up.
Remove underground organic matter, such as dead tree roots or stumps, that the fungus feeds on.
Reseed

In extreme cases

Remove the grasses’ roots containing white, cottony mass of mycelium (fungus).
Dig as much as twelve inches and one to two feet on each side of the ring.
Mix the top six to eight inches of soil with a rototiller.
Reseed or put new sod in the area

If You Can’t Beat ‘Em, Eat ‘Em? Maybe Not

Fairy ring mushrooms may be edible…or poisonous, as mushroom rings can be formed from any of several hundred kinds of mushrooms, from delicious to deadly. Even if your mushroom identification skills are up to snuff, unless you’re willing to eat whatever has found its way to your lawn (pesticides, herbicides, and dog pee are all likely absorbed by the mushrooms)—don’t risk it.

Need More Info?

Check out OSU’s Extension Service’s free “How to Manage Mushroom Fairy Rings in Lawns: Will You Live with Or Manage Them?” (https://solvepestproblems.oregonstate.edu/lawn-problems/mushroom-fairy-ring) publication. It offers detailed advice on what fairy rings are and what to do about them.

This article draws heavily from that.

Love ‘Em or Leave ‘Em?

You might decide perhaps a lawn won’t thrive where you’re getting fairy rings and opt for another way to landscape that area, like rocks or bark. Or maybe you still want your lawn, even if you decide getting rid of your fairy rings is more trouble than it’s worth. Perhaps then some starry night you can join some the fairies and dance around your lawn…. In the darkness, who cares if you’re a lousy dancer and your lawn is less than perfect?

Dana Greyson is a Wasco County Master Gardener who does not have a proper lawn.