Hello,

Tall fescue is a clumping perennial cool-season turfgrass that can be problematic in lawns due to its coarse texture and aggressive growth habit. It tends to form clumps and does not mix well with other turfgrasses, making it noticeable and often objectionable. More information at this link:

Tall Fescue - Turf (msu.edu)

Why it spreads in your lawn:

Tall fescue expands through tillering (the growth of shoots from the base of the plant) and seed production.

It’s a bunch-type grass that doesn’t produce stolons or rhizomes, which means it grows in clumps rather than spreading out thinly.

In the summer, especially during drought conditions, tall fescue may remain green while other cool-season grasses go dormant, making it more visible. More information at this link:

Pain in the grass: Tall fescue - Plant & Pest Diagnostics (msu.edu)

How to stop its spread:

Physical Removal: Dig out the grass clumps with a shovel for small infestations, ensuring that the entire crown and top few inches of roots are removed. Then, add soil and replant with the desired grass seed.

Herbicide Application: A nonselective herbicide such as glyphosate can kill the grass for larger infestations. However, this will also kill the lawn grass, so it should be applied precisely to affect as little of the desired grass as possible. More information at this link:

Pain in the grass: Tall fescue - Plant & Pest Diagnostics (msu.edu)

Cultural Practices: Standard recommendations like increased fertility and mowing frequency will improve the quality of the tall fescue and the surrounding turf, so these methods are ineffective in removing tall fescue. More information at this link:

Tall Fescue - Turf (msu.edu)

Remember, when using herbicides, always read and follow the label instructions carefully to ensure safe and effective application. If you’re unsure or need further assistance, consulting with a lawn care professional and/or certified pesticide applicator can provide additional guidance tailored to your situation.

I hope this helps!