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 look like?

Irregularly shaped, pale pink areas of turf with the leaves of the grass often dying and matted together by fungal growth occur in the growing season.

Often there are pink fluffy fungal growths or coral red needlelike outgrowths, which give the disease its name of red thread.

Why has red thread affected my turf?

Low nitrogen fertility encourages red thread disease. Low fertility often leads to more dead leaf 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, and then not reappear for some time.

How can I avoid red thread developing in my lawn?

The condition of the soil under the turf is very important in defending against disease attack. A well structured, freedraining soil will help to produce healthy turf. Using a preturfing fertiliser will help prevent its development on less fertile sites.

Once the turf has rooted down and established, the lawn should be fed occasionally in the normal way using a fertiliser with a high nitrogen content.

Can I control it chemically?

There are currently no fungicides recommended for use by amateur gardeners in the UK to control red thread.

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

Should I blame the turf grower for the disease on my turf?

Only if the symptoms were present on delivery or developed within a few days afterwards.


The development of this disease is related to the fertility of the soil where the turf has been laid.

However it is commonly found on various types of turf surface and it may occur naturally anywhere.

Produced for the TGA by independent agronomist Robert Laycock, member of RIPTA (