Creeping bentgrass (Agrostis palustris) is a thin-bladed perennial grass that is usually quite invasive. It spreads into areas of more desirable bluegrass, choking them out. Bentgrass is occasionally used as a lawn grass in states with milder, moister climates, but rarely here. To thrive and look good it needs a very high level of maintenance, including frequent, short mowing and frequent fertilizing. A more desirable variety of this bentgrass is widely used on golf greens here and throughout the world.

There are two ways to rid your lawn of creeping bentgrass patches. One approach to controlling them is to spot treat with glyphosate (sold as Monsanto Roundup). Glyphosate is a non-selective herbicide. Most plants, grassy or broadleaved, desirable or undesirable, will be damaged or killed when glyphosate is applied to green, living tissue.

To spot-kill patches of bentgrass, use a hand-held sprayer close to the ground. Or mix a small amount of the weedkiller in a bucket and use a paint brush or a sponge fastened to a stick to apply the solution directly onto the plants you wish to eliminate. (There is no need to soak it into the soil.) Be careful not to get it onto anything else.

Areas treated with glyphosate may be re-seeded seven days after the chemical has been applied. You may wish to wait till the bentgrass is totally brown, though, and reapply the glyphosate if parts are still living.

The other option is simply to dig the bentgrass out, roots and all. Any roots remaining can sprout and cause further problems, however. Bare areas may then be seeded or sodded.