How to Identify Red Thread Lawn Disease

The threads or tendrils that grow atop red thread-infected turf grasses are called sclerotia. These threads are red or pink in color and give the disease its name. The condition is usually visible with the naked eye, although there are other lawn diseases with a similar appearance including dollar spot, pink patch, and pink snow mold. By taking a closer look at the infected grass, you will be able to identify Red Thread by the distinctive red or pink threads (sclerotia) or the small, pink, cottony puffs (mycelia) that can also form at the tips of leaves.

When Red Thread infects a grass plant, blighted spots may appear on the leaves of grass as quickly as two days. These spots will appear on the leaves, stems, and leaf sheaths of the plant, but do not infect the roots or crown (the base of each grass plant from which it grows) and may not always cause plant death.

During drier days within its livable season and conditions, a Red Thread disease outbreak will often result in the dying off and fading in color of most afflicted blades of grass. Infected grass blades may appear in patches or more randomly intermixed with healthy grass, depending on the spread of the disease. Infected patches of grass will usually be circular in shape on the lawn.

In more humid climates, turf blade death is less likely, and the infected turf plants will soon produce the signature red or pink tendrils or threads or cottony mycelia from their tops. These more visible signs are the clearest indicator that you are looking at Red Thread lawn disease. Check our following page on How to Treat Red Thread for DIY treatment tips.