Red Thread Disease of Lawns - Laetisaria fuciformis Fungal Disease.

Red Thread normally attacks lawns made of fine grasses such as the Fescues, and some Ryegrasses. It is more likely on turf that is rarely - if ever - fed! Again we are back to a good maintenance regime to prevent this particular disease.

Identifying Red Thread Disease

It is the most likely of the fungal diseases to cause brown patches, and is easily identified. The light brown patches will be noticed first, and on inspection, you will notice distinct signs of the fungi which gives this lawn disease the common name of Red Thread. The first stage of infection, will result in red threads reaching out from the dead blades of grass.

These can remain active in the lawn soil for two years. Afterwards, there will be signs of a fluffy pinkish growth. Initially the affected areas will be yellowish brown patches. If not treated, then these will spread to join up across the lawn.

It is usually a problem on such lawns in the year following a hot, dry summer. Normally in moist periods, there will be the tell-tale signs of the red threads.

In the late autumn months, look for patches of bleached out grass which will have small red or pink rigid growths in moist weather conditions. The areas start as small as 1in across - soon spreading.

Whilst the fungus - Laetisaria fuciformis is the fungus that causes the disease of Red Thread. It used to carry the name of Corticium disease. This is a mix up along the way, in that Laetisaria fuciformis is a member of the greater Corticium group of fungi.

In the growing season, Red Thread disease can be kept under control - even eradicated - by a good feeding regime for the lawn. This will strengthen the grasses and help a lot in negating the Red Thread disease.

After feeding, the affected areas often turn into straw-like grasses. These will soon be removed by normal mowing. The grass will return to its 'normal' green colour.

Copyright - PennState Agricultural College - Plant Science Dept.

Prevention and Control of Red Thread Disease.