Fairy Ring: Identification, prevention and treatment
General Description
Fairy Ring is a broad term used to describe multiple diseases that are caused by various soil-borne organisms. The Fungi that cause fairy rings are classified as basidiomycetes. There are 4 types (including thatch fungus) and it’s important to diagnose which one you are affected by….
What are the symptoms?
Type 1:
These typically have a ring of dead grass or bare soil between areas of stimulated grass growth. This comes from the release of nitrogen from the dying areas
Type 2:
These are typically rings of stimulated growth which are noticeably darker than surrounding turf.
Type 3:
You wont necessarily notice an obvious pattern to these, but they will be characterised by the mushrooms that form in the typical circular shape.
Type 4 / Thatch Fungus:
You may also observe a superficial fairy ring more similar to type 2 that can be green or yellow caused by fungus feeding on the thatch layer, this thatch fungus has a musty smell.
What are the susceptible grass species?
All turf grass species are susceptible to fairy ring diseases.
What time of year and under what conditions do they appear?
Type 1 in particular is most apparent in dry summer weather, Type 2 in summer and autumn and Type 3 aswell as thatch fungus at more or less any time of the year.
What are the effects on turf?
Type 1 are the most worrisome as they create areas of bare soil that will impact playability. Often associated with drought conditions as this is when they are most apparent, the organisms feed off the organic matter in the soil and create hydrophobic conditions meaning the soil ends up repelling water.
While type 2 and 3 are unlikely to disrupt play they will have an impact on presentation and like all Fairy Rings they will grow in size annually getting bigger and spreading year on year although they may not always form perfect rings.
Management
Using the information above confirm what fairy ring you have, you are also likely to observe white mycelium in the soils as seen below if you have Type 1, this is the fungal organisms in the soil. Complete removal is difficult to achieve so management practices need to be implemented to lessen the impact of the problem and reduce the conditions in which fairy rings spread.
Cultural
💡 Fairy rings are associated with high thatch levels as seen above and high organic matter so monitoring and treating these is key, think scarification, verti-cutting, surface aeration, soil analysis etc.
💡 They are also often found where old tree stumps have been left.
💡 Deep spiking to aid water penetration and improve the break down of organic matter in soils.
💡 Adequate irrigation and turf nutrition will help to mask the symptoms of type 2.
💡 Removal of mushrooms through mowing will often be adequate for type 3 fairy ring.
💡 As above thatch fungus can be addressed by reducing/removing the thatch layer.
💡 Type 1 can be dug out, but this is a major operation as soil may need to be removed and replaced up to 60 cm deep from the whole ring including a small buffer zone from outside the ring.
Chemical
💡 Specialist wetting agents are specially formulated to hydrate the water repellent waxy deposits created by fairy ring fungi for types 1 and 2 and offer additional benefits to help create conditions to allow the fairy ring to break down naturally.
💡 There is limited evidence to show that fungicide application is effective on fairy ring turf disease. Certain fungicides may reduce the effect of type 2 rings on turf.
