Lawn Diseases

Red Thread

Red Thread
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Red Thread Disease is a fungal infection found on lawns and other turfed areas. It is caused by the corticioid fungus Laetisaria fuciformis and has two separate stages. The stage that gives the infection its name is characterized by very thin, red, needle-like strands extending from the grass blade. The other stage is visible as small, pink, cotton wool-like mycelium, found where the blades meet. It is common when both warmth and humidity are high.

The first signs of infection are small irregular patches of brown/yellowing grass. Upon closer inspection, either the tiny red needles or the pink fluffy mycelium will be visible. As the infection spreads, the small patches will join to form large brown areas.