Tulsa Lawn Care Update - Fairy Rings
Fall is here and with it comes some rainy weather and overcast days. When weather conditions are just right, you may seem some mushrooms in your lawn. Mushrooms are the fruit of beneficial fungi under your lawn that break down organic matter.
Recently we have seen fairy rings in several lawns. Fairy rings may show up as an arc or, more commonly, circles of darker green grass in your lawn, or as circles of brown grass, or as circles of mushrooms. You may see this as either a lovely natural phenomenon…or an unsightly nuisance!
Image: Wikimedia, Kelisi
Fairy rings are caused by many different varieties of the fungi Basidiomycetes. Mycelia is the vegetative part of the fungus colony which consists of a mass of thread-like hyphae. These fungal masses (sometimes called shiro in fairy rings) under the soil can be massive! In eastern Oregon, there is such a mass that is 2,200 years old and estimated to be as large as 1,665 football fields! Yikes!
Anyway, the mycelia absorbs nutrients from rotting matter – the hyphae secrete enzymes onto the food source, breaking it down, so the mycelia can absorb it.
Fungi are very important in the process of breaking down organic matter, which produces nitrogen (like fertilizer); hence, the ring of darker green grass.
If the fungal mass gets very dense, it may prohibit water movement in the soil; hence, the brown grass. Also, the mycelia of some fairy ring fungi is hydrophobic, meaning it becomes impervious to water, resulting in drought stress for the grass.
Many times, fairy rings are found in areas that were previously wooded and then cleared to build homes.
Interestingly enough, fairy rings will not cross each other, because when fungi from different rings come in contact, the fungal activity ceases.
NOTE: never eat mushrooms you find in the lawn. Many poisonous mushrooms look just like non-poisonous mushrooms, and it may even be difficult for an expert to tell the difference!
Image: Wikimedia, Mrs. Skippy
How can you get rid of fairy rings?
Frankly, you can look all over the internet on many knowledgeable university websites and not really find anything that consistently works.
- Fertilize the surrounding grass to even up the color
- Pick the mushrooms
- Aerate the lawn for better water absorption
- Poke holes in the ring with a lawn fork 12” to 24” deep and then water heavily for 4-6 weeks
- Use a fungicide (very little proof that this works at all)
- Eliminate thatch build-up by dethatching (do NOT do this to fescue or to bermuda in the fall since it will go dormant soon and will not recover)
- Remove existing turf, excavate to find undecomposed tree roots or buried construction debris, and renovate the lawn by sodding.
Look on the bright side – fairy rings are supposed to be good luck! (But don’t step inside the ring on Halloween – that can be very dangerous!)