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Fairy rings are one of the most distinctive and frustrating lawn problems you’ll encounter. Those mysterious circles of darker green grass, sometimes accompanied by mushrooms, are caused by soil-dwelling fungi and can persist for years. Here’s what causes them and what you can realistically do about them.
What Are Fairy Rings?
Fairy rings are circular patterns in lawns caused by fungi growing outward through the soil. The fungus starts from a central point, often a buried piece of wood or organic matter, and expands in all directions, creating an ever-widening ring.
The visible symptoms appear at the outer edge of the fungal colony where it’s most active. As the ring expands outward each year, typically by 15-30cm, the centre returns to normal because the fungus has exhausted the nutrients there and moved on.
Fairy rings are named from folklore that attributed the circles to dancing fairies. The reality is less magical but no less interesting. Over 60 different fungi species can cause fairy rings, each behaving slightly differently.
The Three Types of Fairy Ring
Not all fairy rings cause the same symptoms. Turf professionals classify them into three types based on the damage they cause.
Type 1 fairy rings are the most destructive. The fungal growth creates a water-repellent layer in the soil that prevents moisture reaching grass roots. The result is a ring of dead or dying grass that’s extremely difficult to rewet.
Type 2 fairy rings show as rings of darker green, more vigorous grass. The fungus breaks down organic matter in the soil, releasing nitrogen that fertilises the grass above. These rings are unsightly but don’t kill the turf.
Type 3 fairy rings produce only mushrooms or puffballs in a circular pattern without any visible effect on the grass itself. These are purely cosmetic and the easiest to live with.
Why Mushrooms Appear
The mushrooms or toadstools you sometimes see are the fruiting bodies of the fungus, appearing when conditions suit reproduction. They typically emerge in autumn after rain, though some species fruit in spring.
Not all fairy rings produce visible mushrooms. Many never fruit above ground, so you might have fairy ring fungus without ever seeing toadstools. The dark green ring or dead grass band is often the only visible sign.
If mushrooms appear, you can simply knock them over or mow them off. This doesn’t affect the underground fungus but removes the visible nuisance. Some fairy ring mushrooms are poisonous, so remove them if children or pets use the lawn.
Treating Type 2 Rings (Dark Green Circles)
The dark green rings of Type 2 fairy rings are the most common and fortunately the easiest to manage. The key is masking the colour difference rather than eliminating the fungus.
Regular lawn feeding makes the rest of the lawn as green as the ring, effectively hiding it. A nitrogen-rich feed applied to the whole lawn evens out the colour difference. The ring is still there but becomes invisible against the uniformly green background.
This approach works remarkably well. Most people with Type 2 fairy rings find that proper feeding makes the problem disappear visually, even though the fungus remains active in the soil.
Treating Type 1 Rings (Dead Grass)
Type 1 fairy rings with dead grass bands are much harder to treat because the fungus creates hydrophobic (water-repellent) soil. Water simply runs off rather than soaking in, and the grass dies of drought even when the surrounding lawn is well watered.
The treatment approach involves breaking through the hydrophobic layer. Spike the affected ring heavily with a garden fork, pushing as deep as possible. Then apply a wetting agent (available from garden centres) which helps water penetrate the resistant soil.
Follow up with thorough watering, forcing moisture down through the spike holes. Repeat this process several times over a few weeks. The aim is to rewet the root zone so grass can recover.
For severe cases, you may need to strip the affected turf, remove the top 30cm of soil, replace with fresh topsoil, and reseed or returf. This is drastic but sometimes the only effective solution for persistent Type 1 rings.
Aeration and Cultural Control
Regular aeration helps prevent and manage fairy rings. Good soil drainage and air movement create conditions less favourable for the fungi.
Removing buried organic matter eliminates potential starting points for new rings. Old tree stumps, buried wood, and thick thatch layers all provide food for fairy ring fungi. Scarifying to reduce thatch removes one potential food source.
Improving drainage through aeration and topdressing with sand helps water move through the soil rather than sitting in layers where fungi thrive.
Chemical Treatments
There are no fungicides approved for home gardener use against fairy rings in the UK. Professional turf managers have access to some treatments, but these are expensive and results are inconsistent.
The fungi responsible for fairy rings live deep in the soil, beyond the reach of most surface-applied products. Even professional treatments often provide only temporary suppression rather than elimination.
For most home lawns, cultural approaches combined with feeding to mask symptoms are more practical than seeking chemical solutions.
Living With Fairy Rings
It’s worth accepting that complete elimination of fairy rings is often impossible without drastic soil replacement. The fungi can persist for decades, slowly expanding year after year.
For Type 2 and Type 3 rings, the practical approach is management rather than eradication. Feed well to mask colour differences, mow off any mushrooms, and accept that the underground fungus will continue doing its thing invisibly.
Many lawn enthusiasts learn to see fairy rings as interesting natural phenomena rather than problems requiring fixing. In meadow lawns or wilder gardens, they add character. It’s mainly on formal lawns where the visual impact becomes frustrating. For other fungal lawn problems like red thread and fusarium, different approaches apply.
Preventing New Fairy Rings
While you can’t always prevent fairy rings, reducing risk factors helps.
Remove old tree stumps and buried wood during garden construction or renovation. These are common starting points for fairy ring colonies.
Maintain good lawn health through regular feeding and autumn care. Healthy, well-nourished grass is more resilient to fungal activity and recovers faster from any damage.
Keep thatch under control through regular scarification. Thick thatch provides organic matter that some fairy ring fungi feed on.
Ensure good drainage. Waterlogged soil favours many fungal problems including some fairy ring species. Fixing drainage issues benefits overall lawn health. For more fungal lawn problems and solutions, browse our lawn care problem-solving guides.
Autumn is the ideal time to build disease resistance. Our Autumn Lawn Treatment feeds roots, hardens grass for winter, and helps create the dense, healthy turf that’s naturally more resistant to fairy rings and other fungal issues.
