How to prevent, treat and control lawn disease
Our guide to the most common lawn diseases
Just like other plants in your garden, lawn grasses can suffer from diseases. The good news? Most won’t cause serious long-term damage, especially if your lawn is well cared for. A strong, healthy lawn is the best defence, so regular feeding, aeration, scarifying and a proper mowing routine are key.
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Red thread
One of the most common fungal diseases, red thread thrives in nitrogen-deficient lawns, especially during damp summers and autumn. It appears as reddish patches that later turn light brown or bleached, sometimes binding the grass blades together. While it looks alarming, it rarely kills the grass completely.
Control
Although there are no chemical products available to the home gardener there are steps you can take to help.
- Apply a nitrogen-rich lawn feed to strengthen the grass such as Miracle-Gro® Fast Green Lawn Food Concentrated Liquid.
- Improve drainage by aerating compacted areas.
- Mow regularly.
- Over seed bare batches after scarifying.
Fusarium patch (snow mould)
This fungal disease often shows up in autumn and winter, causing yellow patches that later turn brown. During wet conditions, you might notice white or pinkish fungal growth at the edges of the affected areas. If left unchecked, large sections of your lawn can be damaged.
Control
As with red thread, there are no chemical products available to the home gardener but there are steps you can take to help.
- Avoid excessive autumn feeding, as lush growth is more susceptible.
- Improve airflow by Scarifying (raking out) thatch in the early autumn and aerate the soil.
- Reduce damp conditions by clearing leaves and avoiding waterlogging.
- Rake over the bare patches and over seed in the early autumn or spring with a shady lawn seed such as Miracle-Gro® Shady Lawn Seed.
Fairy rings
These mysterious rings of dead grass, often accompanied by toadstools, appear in late summer and autumn. The grass around the ring may turn greener than the rest of the lawn, and the circles slowly expand each year.
Control
Although there are no chemical products available to the home gardener there are steps you can take to help.
- Knock or kick over the toadstools before they mature and spread spores.
- Aerate the lawn to break up fungal networks.
- If the rings are small, rake and reseed the area. For larger rings, patience is key as eventually they will grow beyond your lawn’s boundary!
Although Fairy ring toadstools aren’t poisonous it’s always advisable to dispose of them carefully to prevent children and pets eating them.
Take-all patch
Although Take-all patch is one of the most damaging lawn diseases, it is not that common. It first appears in mid-summer.
Take-all patch is caused by the fungus Gaeumannomyces graminis. It first appears as small circular patches, expanding to around 50cm to 100cm (20in to 40in) in diameter. It mainly affects bent (Agrostis) type grasses, producing dying areas of straw-coloured grass. Take-all patch will eventually disappear after December but can keep coming back for several years.
Control
If you do have this disease, when you re-seed the bare patches, always choose a hard wearing mix with a very high percentage of perennial rye grass such as Miracle-Gro® Multi Purpose Lawn Seed.
Lawn health = disease prevention
A well-fed, scarified, aerated, and regularly mown lawn is far less likely to suffer from disease. Keep an eye on problem areas, act quickly when issues arise, and your lawn will stay lush and green all year round!
Top lawn care tips
- Keep the lawn at an even, balanced length -avoid scalping the lawn as this weakens the grass and makes it more vulnerable to damage, encouraging not only disease but also weeds and moss.
- Ensure the lawn is well fed all year round by using a lawn feed in spring and summer. But avoid high doses of nitrogen fertiliser in late summer or autumn - always use an autumn lawn feed such as Miracle-Gro® Autumn Lawn Care instead.
- Poor drainage and compacted areas will encourage diseases and reduce grass health, so improve drainage by spiking the lawn with a fork, or hire a hollow-tine aerator in autumn.
- Thatch(dead material) can encourage lawn diseases, so scarify with a spring-tine rake or electric scarifier in autumn and spring to remove moss, dead leaves and any other dead material.
- Disposing of grass cuttings will reduce the amount of fungus present to re-infect the lawn but if you do have fungal disease present, don’t compost the lawn clippings.
