Our Grass

Question

We live in Zone 5, a suburb of Chicago. We basically have a Kentucky bluegrass lawn mixture. The lawn is over 40 yrs old. It was originally a sodded bluegrass lawn. Through the years, I find clumps and areas of creeping bentgrass growing. For me, I consider it a weed and prefer a more uniform appearance. The bentgrass is around the neighborhood, as close as next to me. I find myself pulling it and cutting it out of the lawn and then reseeding.
It’s ongoing, and I wonder if there is something else I could be doing to maintain my bluegrass mixture (creeping grass free). Your expert advice will be greatly appreciated.

Thank you,
Shel

Answer 1

There is an herbicide available called mesotrione (sold as Tenacity) that will kill creeping bentgrass specifically but will not kill bluegrass. If you can't find Tenacity, another option is to kill the creeping bentgrass patches with an herbicide that contains glyphosate. Glyphosate will kill the bluegrass as well, so you'll have to reseed it later.

Apply the herbicide in a ring six inches around the patch as well to kill any runners too.

The other option is, of course, to hand-remove all the patches of bentgrass you can find.