thread is a relatively new fungal disease to our region, but seems to
be on the rise in urban areas. Almost all grasses can be affected,
however Fine Fescue seems to be a preference for this disease. It
generally is found on nitrogen deficient grass during cool, moist
fungus over winters on the blades of grass and in the thatch layer.
Only the leaf blade and the sheath appear to be affected. The leaf
blade becomes covered with a pink growth, which forms a thread-like
material as the fungus dries out, hence the name "Red Thread". As the
disease progresses, the grass will gradually dry out creating a tan
appearance to the lawn in areas from a few inches to at the extreme,
most of the lawn.
Thread is best controlled by proper cultural practices, including
regular fertilization. Watering the lawn deeply once a week will ensure
the soil remains moist, but the surface stays dry. The best time to
water will be in the morning. Watering at night will leave the grass
blade wet for too long a period and encourage fungal growth. Also
ensure your lawn mower blade is sharp. A dull blade will rip or tear
the tips of grass, creating an opening for the disease to develop.
Apply fertilizer on a regular basis, generally every 4-6 weeks. If Red
Thread is present in the lawn, bag the clippings of the next two cuts
to get rid of the fungus on the tips of the grass blade. Make sure to
dispose of the clippings in a non-grassy area.