Fairy Rings

Fairy rings occupy a prominent place in European folklore as the location of gateways into elfin kingdoms, or places where elves gather and dance. According to the folklore, a fairy ring appears when a fairy, pixie, or elf appears. It will disappear without trace in less than five days, but if an observer waits for the elf to return to the ring, he may be able to capture it.

In reality, in your yard, fairy rings are an ugly pain in the butt. And I know, because we have them. They appeared in our yard after the very very dry summer of 2008 and have reappeared every year since. Here are some resources for you. The most effective, in our experience, is the second suggestion, but it requires a lot of care and attention. Alternatively, you could subscribe to the notion that your yard has been blessed by the dance of fairies. Whatever works for you--best of luck!

Symptoms and signs

Fairy rings typically appear as rings of dark green and fast-growing turf. They may also appear as rings of slow-growing or killed turf. The bands of affected turf are from 4 inches to a foot in width, forming more or less continuous rings ranging from 3 to 200 feet across. In some instances, the center of a stimulated band may contain weakened or dead grass, or bands may have an inner zone of stimulated grass edged with dead or stunted turf on either side.

Mushrooms produced by fairy ring fungus.

The first visible evidence of a new fairy ring is usually a cluster of mushrooms or toadstools. They usually appear at the outer edge of rings in late summer or early fall, during periods of high soil moisture.

Disease cycle

Fairy rings are produced by colonies of mushroom fungi that live in soil and thatch. These colonies obtain food from decaying organic matter and grow outward radially, increasing in size year after year. The ring of stimulated grass is thought to be caused by nitrogen substances produced by the breakdown of organic matter by the fungi. The fungi usually do not attack grass, but sometimes they repel water, resulting in death of the turf due to drought. The causal fungi are spread when fungal threads, bits of mushrooms, or spores from the mush- rooms are introduced into soil under a turf area.

The telltale circle of mushrooms eventually leaves a ring of dead grass. There are plenty of old wives’ tale cures from boiling water, digging, watering, special tools…the list goes on and on. There is no simple solution that really works well. Fairy rings are caused by mushroom fungi; yet there are no fungicides that will control the mycelium, or underground growth of the fungus. Heavy fertilization and watering can help.

Control:

1. Dig it Out: I’ve used this method the most successfully. I call it part of Tam’s spa program. If you are highly energetic, considering exercise, and own a wheelbarrow, you may decide dig out the fairy ring. You must remove the fairy ring turf and soil for 18 inches on both the inside and outside of the ring. The soil should be removed to a depth of at least 2 inches (5 cm) below the zone of the white fungus mat that you’ll discover when you start digging. When removing the affected areas, try to prevent any of the turf or soil from spilling onto healthy areas. Fill the area with fresh top soil and then reseed or re-sod.
2. Drown it Out. The roots of the fairy ring (mycelium) actually repel water, which is what causes the grass to die out. To overcome the extreme drought conditions, use a root feeder or garden fork to punch holes in the fairy ring every 4-6 inches (10-15 cm) apart and 10 inches (25 cm) deep. Soak the holes every second day, if not every day, for at least a month, especially if the fairy ring had progressed to the dried grass stage. Add a teaspoon of liquid dish detergent in a gallon of water to act as a wetting agent to help the water soak into the infested soil. A complete soaking of the area, in addition to a fertilizer application can not only suppress but may even eradicate the fairy ring
3. Wait it Out: Fairy rings will tend to die out naturally when they encounter sidewalks, flower beds and other cultivated areas. Lots of folks extend their flower beds to include fairy ring areas.
4. Duke it Out: I found this one online: Another possible method of eradication is based on the fact that when 2 rings come into contact with each other, they will exhibit antagonistic behavior, which leads to the death of both rings. To take advantage of this natural control method, one may wish to remove the sod in heavily infested areas, cultivate the soil several times to mix the mycelium of one ring with another and then re-seed or re-sod. Really?

Whatever method of control is employed, good turf management practices should follow to ensure re-infestation does not occur. This includes a regular fertilization program in addition to irrigating to a depth of 6 inches (15 cm). Shallow watering should be avoided in all instances.

But there is good news on the horizon. There has never been a cure. Until now, that is. While researching the fungus that causes blackleg in canola, Prem Kharbanda, of the Alberta Research Council, accidentally came across bacteria in a soil sample from central Alberta that not only stopped black leg in its tracks, it also disabled fairy ring.

Prem is experimenting with the bacteria to determine the most effective way to administer it to the soil to kill fairy rings. It will take at least two or three years before the Alberta Research Council confirms their result, and after that, another couple of years before it can pass through the federal government registration protocols.

Dr. Prem Kharbanda is a Senior Scientist with the Alberta Research Council.

(Via Prairie Gardens )