What Causes Fairy Rings on a Bowling Green?

  • By: Jack Toucher
  • Date: June 8, 2023

Fairy rings appear for apparently no reason at all on well-kept greens, causing anxiety in the green keeper and the players alike. They are caused by a fungus and are difficult to get rid of.

The appearance of some types of fairy rings (such as shown in the image above) do not necessarily affect the running of the bowls. But some types of fairy rings require closing the green while the condition receives treatment, or waiting for the problem to solve itself over time.

Fairy rings on bowling greens

To get an intelligent, scientific answer to the vexing question of what to do about fairy rings on a green, I referred to Dr Charles Louw’s book named Lawn Bowls: Greens Management. Here is what he says:

One or more of about a dozen fungi that feed on decaying organic material can cause Fairy Rings.

Most of these fungi belong to the basidiomycetes group. They are normally
characterised by dark arc-shaped rings appearing in the spring or early summer with
or without a paler area inside the darker ring.

The fungus may grow deeply in soil with a dense, white threadlike network of mycelium. As the fairy ring fungus grows outward, it leaves behind older mycelium in the inner ring. These mycelia die, and as they decompose, they give off nitrogen, which gives the grass the dark green colour.
This proves that the active portion of the fairy ring is actually outside the ring that we see.

Symptomatically three types of Fairy Ring are recognised.

Type I Fairy Ring

This type of fairy ring causes the soil and thatch to become hydrophobic, killing the turf in patches, rings, or arcs. In areas affected by a Type I Fairy Ring, the thatch and soil are extremely dry and repel water.

Type II Fairy Ring

This type of fairy ring (as illustrated in the image above) appears as rings or arcs of turf that are
dark green and growing more quickly than the surrounding turf.

Type III Fairy Ring

These fairy rings are characterised by mushrooms or puffballs produced
in a ring or arc as per the photo here.

The type of symptom expressed by a particular Fairy Ring may change during the year according to weather conditions. Type III Fairy Ring symptoms are more prevalent during extended periods of wet weather. Type I and Type II Fairy Ring symptoms are most common during hot, dry weather in the summer.

Control and eradication

Control of Fairy Ring are very difficult. The only assured way of getting rid of Fairy Ring is to remove that portion of the turf, sterilise the soil, and replant. Some success has been achieved by applying a seaweed fertiliser with Fulvic acid plus a micro-organism monthly during the growing season.

Limited success has been achieved by aerating an area about 300 mm wide just outside the dark ring and to a depth of 200 mm. This area should be watered well with a wetting agent and a fungicide, for example, azoxystrobin (Heritage).