Red Thread Disease: What are the symptoms and how to treat?

Red thread is a fungal patch disease that affects lawns. It gets its name from its distinctive red-pink colour. You may also see brown patches of grass. It thrives in wetter and warmer conditions, making it a common sight in the summer and autumn seasons in the UK. With the right treatment, you can get your lawn back to its usual healthy state and prevent it from spreading. With red thread disease most likely to occur now, it’s good to watch out for the signs and protect your lawn. In this guide, we’re sharing how to treat and protect your turf. 

What is red thread disease and where does it come from?

Red thread, or Laetisaria fuciformis, is a fungal disease that affects grass. It’s most likely to affect grass that is deficient in nitrogen and typically strikes in the summer or autumn. 

What are the symptoms?

There are a range of symptoms to look out for, including small, pink, cottony flocks. Alternatively, you may see pink-red threads. These are known as stromata. These can remain on leaves and in the soil for up to two years. The grass may lose its colour, resulting in unsightly brown patches. 

It’s best to check whether this is a result of snow mould or red thread, as each of these will require different treatments. 

How to treat it

You may not need to take action. The roots of your grass should not be affected, and in some cases, the disease will clear on its own in a few days. However, if any patches persist, treatment will be required. 

There are chemical treatments available, and these should be applied in a highly-controlled manner by professionals. 

Prevention is the best cure

Red thread typically grows and thrives best on wet leaves. Regular garden maintenance, including collecting leaf debris off the lawn, can help minimise the spread of this fungal disease. 

 Making sure your grass has sufficient amounts of nitrogen can help treat the affected areas. Nitrogen is a powerful nutrient for grass, as it gives it its vibrant colour and helps to strengthen the blades. 

We recommend a summer fertiliser that is rich in nitrogen.