Lawn Problem: Red Thread

How do I know if my lawn has Red Thread?

Red Thread will present itself as random areas of dead and dying grass with a pinkish/brown tinge. Outbreaks normally follow wet and warm conditions. It can occur at any time of year if conditions are right, but it will normally attack between March and October.

Close inspection of the affected area will show tiny red strands (red thread) running through the grass blades. It may be accompanied by cotton wool-like growths. If conditions and the fungi have passed, the lawn will just be left with a brown scarring. It is always difficult to be certain at these times but the overall pattern on the grass will give clues as to Red Thread having been present.

The last picture below shows scarring from red thread. It is no longer active here.

What is Red Thread?

Red Thread is a fungal disease which attacks the grass leaf blades. It will not kill the plant. Once present in a lawn, it is difficult to eradicate and so it is much better to keep the lawn healthy with regular aeration and good nutrient availability. This will make it more resistant to red thread and other diseases. Red Thread can be spread by air, water, or infected tools, boots, etc.

How do I cure Red Thread?

Red thread can be controlled by using fungicide applied by a professional Lawn Care company, however, if conditions prevail longer than around four weeks, the fungi will return. At LawnsOne we actively discourage fungicide application. The fungus attacks the leaf blade and rarely kills the plant. Using a balanced feed will help the grass to regenerate quickly and of course, aeration will help the all important root development and surface drainage. A higher nitrogen feed can be used in spring and summer, however, in Autumn the use of iron to strengthen the leaf blade is more desirable as quick lush growth in autumn will make the plant more susceptible to red thread and other ailments.

Key points to remember

  • Keep your turf healthy and well fed to minimise attacks.
  • Feed out in spring/summer, harden off in autumn.
  • Once you have red thread it is likely to remain and appear when conditions are right.
  • This is part of the natural cycle of your lawn.

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