Creeping Bentgrass, more commonly known as Bentgrass, is a perennial cool season grass. This cool season grass is a popular choice of on golf courses (putting greens, tee boxes, and sometimes fairways) but is a less than desirable turfgrass for DIY homeowners.
Bentgrass is a low cut grass that spreads quickly via rhizomes (roots) and stolons, and will eventually take over your lawn– hence “creeping”. This specific type of grass prefers to be mowed very short, and can withstand many of the selective herbicides that you would normally spray on your lawn to kill crabgrass, nutsedge, and other weeds. This is why knowing what bentgrass looks like is really important.
Creeping Bentgrass Identification
Creeping bentgrass has shallow roots and stolons that spread, causing visible patches of lighter green turf in your yard. These stolons act like roots and runners on top of the soil, and shoots grass blades vertically as it continues to creep horizontally.
Bentgrass seeds can be in your soil without knowing, and propagated after core aeration. Seeds can also be mixed in with the bag of grass seeds that you purchase. They are very small and can slip through the screening process and sometimes missed during quality control.
Since bentgrass prefers to be mowed very short (under 1″) the longer grass and its stolons will spread and will be able to lift up almost like a carpet. While the root systems are much more shallow than the rest of your cool season turfgrsasses, the rhizomes spread well beyond what’s visible on the surface. This makes eradication of bentgrass a bit more challenging.
How To Get Rid Of Bentgrass
There are a few ways to get rid of and kill creeping bentgrass in your lawn. Perhaps the best way to get rid of bentgrass while preserving the rest of your lawn is with Tenacity herbicide. This selective herbicide uses an active ingredient called mesotrione which disallows photosynthesis in the plant and disrupts chlorophyll. Some say it’s like a person using sunblock.
Spray two applications of Tenacity – two weeks apart – with a non-ionic surfactant (NIS).
I used this method with great results back in 2019 – check out my full Tenacity Herbicide review here. After several days, the bentgrass will begin to turn white. And soon after the second app, the grass will turn brown and eventually die. Scalp the grass with your lawn mower, use a dethatch rake or Sunjoe to remove the excess grass (hay), and spot/overseed the bare areas.
The next is by using a non-selective herbicide like glyphosate or Avenger. Spraying the bentgrass with these chemicals will kill the bentgrass. But since they are non-selective, these herbicides will also burn everything else it touches – including your desirable grass. Scalp, rake, and overseed the same as the aforementioned Tenacity method.
Dig and Remove
While less effective, and requiring much more manual effort, you can attempt to dig the bentgrass out. Digging around the patches of bentgrass, removing the roots, and re-seeding with your choice of premium grass seed to fill in and match your existing lawn. However, this method may not completely eradicate the bentgrass. Any roots and rhizomes left behind in the soil will eventually come back and spread.
I hope this helps with the identification of bentgrass and the steps to rid your lawn of this obnoxious grass. Got questions? Please leave them in the comments below.