St Andrews Links Blog

The Fairy Ring

For those of you that have ever wondered what those darker green, circular and wavy patterns on the surfaces are, whether it’s from the aerial view on television or from out playing, this will hopefully answer your question.

This is known as a ‘fairy ring’ and here at the Links, like many other courses worldwide, we have been managing and controlling this turf grass disease for many years.

What is a Fairy Ring?

The name is used to describe a number of turf grass diseases where soil borne fungi cause symptoms to develop on the surface of the grass sward. Fairy rings are caused by the activity of the fungi classified as basidiomycetes.

Each of the individual fungi grow through the soil, feeding off the organic matter as it increases in size. The fungi is made up of compounds (mycelium) that naturally repel water, which creates hydrophobic soil profiles.

It is easily recognisable by its distinct patterns on the grass surfaces. These are usually in a circular shape and dark green. There are 3 different classes of fairy ring and within the 3 classes there are over 60 different types. The most common class of fairy ring found here on the Links is Type 2 (pictured above).

Of the three classes, Type 2 is the least severe.  It rarely damages the grass surface and is more of an aesthetic problem. The reason for the dark green circles is when the fungi grows through the soil/thatch it uses the organic matter as its food source, releasing nitrogen as a waste product which stimulates grass growth above in the circle.

What environment suits them?

Fairy Rings are very common on sand based surfaces, which most of our courses are built on.  They favour soils with high organic and thatch levels, unbalanced moisture levels in the soil profile and other organic debris such as decaying grass on the surface.

Why are they circular?

Fairy ring fungi begins in the soil or thatch and grows outwards, like a patch of mold would grow in an expanding circle on a piece of rotten fruit. When two or more rings meet they do not grow together; this leads to the wavy patterns.

How do we manage and control them?

• Monthly top-dressing applications to maintain minimal organic matter/ thatch levels (reducing its food source) and to improve soil structure.
• Precise water and moisture management, including wetting agent programs which prevent hydrophobic (water repellent) soils.
• Adding moisture to selected areas of greens which involves hand watering and the use of a hydro-ject (water injection machine).
• Aeration (spiking) to create channels for air and water movement.
• There is no effective chemical cure to control them.

 

Above is the hydro-ject which we use on selected areas of greens for the control of Type 2, this injects water at a high pressure into the soil profile creating channels for moisture with minimal disruption to the surface.

 

Words by Gavin Neill, Deputy Course Manager, New and Jubilee Courses