What Is Red Thread Disease and How Do You Treat It on Turf?

Red thread (Laetisaria fuciformis) is a turf disease can occur anytime of the year, in shady, poorly aerated, compacted soils and a lack of nitrogen.

Particularly summer and autumn under warm moist conditions. The main symptoms are irregular patches of light brown or bleached leaves covered with distinctive red threads. Pink patch lacks the characteristic ‘Red threads’. Instead leaves may become coated with pink mycelial growth. Whilst Red thread may occur alone, it often occurs as a disease complex with pink patch.

Severe outbreaks may kill the grass but generally affected turf will recover adequately.

Red thread is more likely to develop on cool, damp turf with low nitrogen levels and shows up as fine red threads on leaf tips or, in severe cases, pink, fluffy patches. To manage it effectively, ensure turf nutrition is balanced, topping up nitrogen can help the grass outgrow and resist the disease, and maintain good cultural practices such as improving airflow, careful irrigation and regular monitoring for early signs.