Pink patches in your lawn?

Red thread disease

What is it?
Red thread disease is one of the most common diseases of turf in the UK. The Latin name of the fungus that causes the disease symptoms is Laetisaria fuciformis. The disease is usually not very harmful and usually causes no permanent damage, but it can be unsightly.

What does red thread disease look like?

Red thread disease forms irregularly shaped, pale pink areas of turf during the lawn’s growing season. The leaves of the grass often die and are matted together by fungal growth. Often there are pink fluffy fungal growths or coral red needle-like outgrowths, which give the disease its name of red thread.


Why has red thread disease affected my turf?

Low nitrogen availability encourages red thread disease. Low fertility in the soil often leads to more dead leaves in the turf, which is one of the symptoms of the disease.

Some grasses are more susceptible to red thread than others. Perennial ryegrass and red fescue, which are commonly used to produce turf for sale, are frequently infected.

The spores of disease fungi are present everywhere and red thread disease may attack a lawn if the climatic conditions are right, even if all the necessary precautions have been taken.


How can I avoid red thread disease developing in my lawn?

The condition of the soil under the turf is very important in defending against disease attack; a well-structured, free-draining soil will help to produce healthy turf.

Using a pre-turfing fertiliser will help prevent its development on less fertile sites. Once the turf has rooted down and established, the lawn should be fed occasionally as recommended using a fertiliser with a high nitrogen content.


Can I control it chemically?

The only chemical fungicide control for red thread disease currently available is Bayer Lawn Disease Control (a.i. trifloxystrobin), available from garden centres. Please follow the instructions when applying this product.

However, it is usually not necessary to use a fungicide for the control of this disease, as it rarely kills the grass outright.



Produced for the TGA by independent agronomist Robert Laycock, member of RIPTA www.robertlaycock.co.uk