You’ve put in the hours. Mowing, watering, feeding, even chatting to the grass when no one’s looking. But one morning you step outside and something’s not right — strange brown patches, odd discolouration, or the grass just looks a bit… ill. Sound familiar? Chances are, your lawn’s got a case of something nasty.
Lawn diseases aren’t just for golf courses. In the damp, unpredictable climate we Brits know all too well, fungal infections and turf diseases are surprisingly common. Here’s how to spot the troublemakers and send them packing.
Common Lawn Diseases in the UK
1. Red Thread
Symptoms: Pinkish or reddish threads growing among the grass blades, often with pale patches of thinning grass.
When: Most common in late spring to autumn, especially in humid conditions or after rain.
What to do: Red thread is often a sign of low nitrogen. Apply a high-nitrogen feed and keep the lawn mown and healthy. It rarely kills the grass, but it does make things look scruffy.
2. Fusarium Patch (Snow Mould)
Symptoms: Circular patches of slimy or matted grass with a white or pinkish fungal coating.
When: Most active in autumn and winter, especially under snow cover or when there’s poor airflow.
What to do: Improve drainage and airflow, rake out affected areas, and apply a fungicide if needed. Avoid overfeeding in autumn — lush grass is more susceptible.
3. Dollar Spot
Symptoms: Small, silver dollar-sized spots (about the size of a 10p coin) that turn brown and merge into larger dead areas.
When: Late spring to early autumn, especially in warm, moist conditions.
What to do: Boost nitrogen levels, improve airflow by cutting back overhanging plants, and avoid watering in the evening. A healthy lawn usually grows out of it with the right care.
4. Fairy Rings
Symptoms: Rings of dark green grass or toadstools. Can also appear as dead patches in a circular shape.
When: Anytime, but particularly during warm, wet weather.
What to do: They’re stubborn. Aerate deeply, water thoroughly, and try a wetting agent to help water penetrate the soil. In most cases, they’re more of an eyesore than a true threat.
What Causes Lawn Disease?
Fungal lawn diseases love:
- Moist, poorly drained soil
- Low airflow and shady areas
- Overwatering or watering late in the day
- Poor mowing practices
- Nutrient deficiencies (especially nitrogen)
In other words, if your lawn is damp, stressed or neglected, it becomes the perfect playground for fungi.
How to Prevent Lawn Disease
As ever, prevention is better (and cheaper) than cure. Here’s how to keep your grass fighting fit:
- Regular aeration: Use a fork or something like the SpikeMat to improve drainage and airflow around the roots.
- Feed smart: Apply the right fertiliser at the right time. Too much nitrogen in autumn can backfire.
- Mow properly: Keep blades sharp, don’t mow too short, and never cut wet grass.
- Water wisely: Water in the morning, not late at night. Let the lawn dry between watering.
- Improve airflow: Trim back hedges or branches that shade the grass too much.
Treating an Infected Lawn
If you do end up with a lawn disease, act quickly:
- Remove debris: Rake up clippings and infected material — don’t compost it.
- Aerate and feed: Help your lawn recover by improving soil conditions and giving it the nutrients it needs.
- Use fungicides (if necessary): Most minor infections clear up with proper care, but persistent cases may need a targeted lawn fungicide. Always read the label and apply only as needed.
Keep Calm and Lawn On
Spotting a disease in your lawn isn’t the end of the world. With a bit of observation, quick action and ongoing care, most UK lawn diseases can be tackled before they take hold. The key is to make your grass strong enough to fight back on its own — and that starts with good habits all year round.
So don’t let a few brown patches ruin your green dreams. Your lawn’s just under the weather — and with your help, it’ll be bouncing back in no time.
