Fungus Alert

Printer-friendly versionDue to the wet weather we have been having, we are noticing many properties with a fungus called red thread popping up. Like most grass diseases, red thread is very much weather related. When conditions are right for development, management of red thread is limited to checking and correcting any nutritional deficiencies or direct treatment with a fungicide material.

When Green Lawns Turn 'Red'
Red thread lawn disease grows most aggressively when temperatures are in the 68 to 75 degree range and during extended periods of wet or very humid weather. Even though this may seem like a narrow "window" or set of circumstances for disease activity, red thread can overtake a turf area fast. Besides temperature, red thread gets a helping hand from certain nutritional imbalances, too. This lawn disease takes off much faster when there's a lack of nitrogen, for instance. Low levels of calcium (or lime) also affect some grass types.

Damage Symptoms: What Red Thread Looks Like And Does
The symptoms of red thread lawn disease first appear as "water soaked" darkened irregular areas from just a few inches to several feet across. These areas gradually become bleached or tan colored. Healthy plants are usually interspersed with diseased plants, giving the lawn an over-all ragged look.

As the red thread becomes well developed, light pink to red fungus strands (or threads) 1/4'' or more in length begin to grow from the tips of the blades and the leaf sheaths - these threads are the reason for the disease's common name. The wind moves bits of these threads to non-infected plants to spread the disease. The threads can also touch nearby blades to spread the infection. Red thread lawn disease very seldom wipes out an entire stand of turf, and so infected lawns will often have an uneven or patchy appearance.