Red Thread

Type: Fungal

Fungal Pathogen: Laetisaria fuciformis fungus

Appearance: Red thread infects in two distinct phases. In the first phase, thin, red, needle-like strands extend from the grass blade. Then, small, pink cotton wool-like mycelium form where the blades meet. Blades appear to die back from the tip of the leaf.

Risk: Bentgrass, bermudagrass, fescues, and perennial ryegrass are at highest risk.

Timing: Spring and fall; When it is warm and humid

Outlook: Red thread can leave behind dead areas of grass. You’ll need to reseed and/or pay special attention to the spots.

How to Control Red Thread


Red thread thrives on unhealthy turf. You can make your lawn healthy enough to fend off red thread with these tips:

  • Water Well: Your grass needs adequate water to thrive. It prefers long soakings about two to three times weekly instead of daily watering, depending on the rain levels from the week.
  • Reseed patchy spots: Grass roots go deep into the ground and take up a lot of space, taking away the valuable real estate weeds need to thrive.
  • Aerate Your Soil: Soil compaction keeps air and water from reaching the deeper levels of soil where grass roots grow, so only plants that grow nearer to the surface, like weeds, can thrive.
  • Check Your Lawn’s pH Level: If your soil’s pH level isn’t neutral (about 7.0), your grass doesn’t have the right environment to thrive, but weeds might. To balance the pH level, your soil may also need applications of lime.


The fungus can survive in leaf blades, thatch, and soil for years, so it is important to cure the infected area so the disease does not spread further. A fungicidal treatment can be used.

Shades of Green Lawn & Landscape knows just how to care for your lawn to prevent and treat fungal infections. And, if you’d like to have your best lawn year-round (one that can fight off red thread!), we have a lawn care package for everyone’s needs and budget. Call us today at 765-771-9998 for a free quote.

Need Help with Red Thread?

Call Shades of Green Lawn & Landscape today at 765-771-9998 and let's talk about how we can help you with Red Thread and other Indiana lawn diseases.

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