Fairy ring is one of the most common and frustrating problems a homeowner can have with their lawn. These unsightly rings can be caused by up to 60 different soil-living fungi. The fungus can create a ring or arc of a deep green turf grass. As the ring progresses through its life cycle, the ring or arc dies out. The ring can vary in size from only a few inches to upwards of 200 feet. Yearly growth is determined by soil type, grass type, and weather conditions. This growth can be between 2 and 20 inches.

Origin of Fairy Ring

Legend tells us that fairy rings were the result of a circle of dancing fairies. It was also believed to be the result of lightning strikes. Science has shown us the dark green circles are a result of fungi growing in the thatch or soil. As these fungi consume organic material in the soil or thatch, they release nitrogen causing the grass to grow taller and greener than the surrounding grass. Adding additional fertilizer to the fairy ring will only hasten its life cycle, and create a dead area. This dead area in turn will usually be taken over by weeds or quack grass. During periods of wet weather or watering, mushrooms will usually appear within the ring. These are the "fruiting bodies" of the fungus. Removing these mushrooms will not weaken the underlying fungus, but does help to improve the appearance of the lawn.

Development

Fairy rings begin from a piece of mycelium feeding in the thatch layer or in the soils organic matter. Organic material, obstructions, soil types, conditions of the lawn all influence how much growth will occur each year. Generally if 2 fairy rings grow into each other they create a scalloped effect. This condition is thought to be due to certain chemicals produced by each fairy ring to inhibit growth of other fungi. The mycelium of the fairy ring creates a layer that is very difficult for water to penetrate. As a result the soil under this layer becomes very dry and is extremely difficult to water, killing the root system of the lawn. Depending on environmental conditions, several years may pass without the presence of the ring or mushrooms. Turf grass that is under stress is more susceptible to fairy ring.

Occurrence

Fairy ring occurs in soils that are high in organic material. They also appear in lawns that have a thick thatch layer. Deep core aeration will alleviate this problem by reducing the thatch layer within the lawn. If you are putting in a new lawn, ensure you remove tree stumps, and discarded building material. The fungi use these objects in later years. Dead or dying tree roots is also a good source of food for the fairy ring fungus.

Control

There are as many homegrown solutions for fairy ring as there are people having problems with this fungus. The reality is there are no sure fired ways to chemically control a fairy ring. There are no products registered within Canada to control fairy ring. Cultural controls are your best bet when dealing with this lawn problem. One method that has some success in controlling a fairy ring is known as the "poke and soak" method. This involves using a soil probe or similar tool to poke holes in the fairy ring. Once this is achieved you soak the area with soapy water. The soap within the water makes it "wetter" helping the water get deeper into the mycelium layer to get to the turf grass roots. This ensures the root structure is receiving some moisture. This method will not eliminate or stop fairy rings from beginning. It simply ensures the grass within the ring is receiving moisture and does not die. Raising your mower to cut higher will also mask the fairy ring. A good well balanced fertilizer program, generally every 4-6 weeks will give the rest of the lawn a deep green color, which again will mask the symptoms of the fairy ring by blending it in with the rest of the lawn. Another option is to remove the ring to a depth of 1 foot and wide enough to extend 2 feet on either side of the fairy ring. Replace the soil with new soil and re-sod or re-seed.

For more information, call the professionals at Ace of Blades at 818-LAWN (818-5296),
or e-mail us at paul@aceofblades.ca.