RedThread [Laestisaria fuciformis]

Red Thread Lawn Disease
Red Thread is one of the most common diseases and is often seen during the summer and autumn months in the UK and is caused by the fungus Laestisaria fuciformis formerly known as Corticium fuciforme. Most types of grass can be attacked by red thread but red fescue and ryegrass are very susceptible. Red thread is most likely to occur in soils that are deficient in nitrogen during cool wet weather conditions. Fortunately red thread is not usually a harmful or damaging lawn disease.

Identification of Red Thread

The first signs of a red thread attack are patches of grass with a tan or pink colour about 20cm in diameter. These patches increase in size when growth slows down, due to the lack of nitrogen especially if the conditions are moist. Red needles or pink webs can be seen between the leaf blades hence the name red thread.

Conditions that favour Red Thread

There are various conditions that this disease favours. These are as follows.

  • A lawn with a high percentage of rye grass or red fescue will be susceptible to red thread disease.

  • A lawn deficient in nitrogen.

  • Red thread favours cool and moist conditions.

Prevention and control of Red Thread

Any kind of chemical control with the use of fungicides is restricted to turf care professionals in the UK. However there are effective cultural methods to control this lawn disease. These cultural methods include:

  • Maintain adequate fertility levels especially nitrogen to keep the grass growing consistently.

  • Improve the drainage to move water through the soil profile and eliminate any water soaked areas.

  • Ensure your mower blades are kept sharp so they cut the grass properly to prevent any damage to the grass leaf.