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Red Thread

Infects lawns across the country

This disease is a parasitic form of plant life called fungi. Fungi live in the soil, thatch and dead leaves all year round. These fungi feed off the grass by drawing valuable nutrients from it.

The disease spreads throughout the lawn in the form of spores. These spores are spread by wind, air, water, and humans. The disease may be caused by improper mowing and by watering during hot, humid weather. Discuss maintenance practices with your Weed Man.

Red Thread attacks most types of grass but is generally found on lawns that contain high proportions of the Fescue & Ryegrass species.

Under ideal conditions, the fungi appear as small red filaments (“threads”) that may be seen projecting out of the affected leaves.

Other factors that may encourage the spread of the disease are poor air circulation, poor drainage and a thatch layer greater than ¼" (1cm).


Controlling Red Thread can sometimes be achieved by changing watering habits, mowing practices, modifying the fertilizer program, providing more air circulation, aeration, and in extreme conditions, applying a fungicide to the lawn. Regular applications of a balanced fertilizer will produce a healthy lawn, which is more resistant to attacks by this disease. Have your Weed Man fertilize your lawn and advise you on correct maintenance to ensure a healthy disease free lawn.