Creeping Bentgrass

Creeping bentgrass (Agrostis palustris) is a thin-bladed cool season perennial grass that is 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 in cool season areas. To thrive and look good creeping bentgrass needs a very high level of maintenance, including frequent, short mowing and frequent fertilization. A more desirable variety of this bentgrass is widely used on golf greens.

Controlling bentgrass?

If you don't live on a golf course and have creeping bentgrass invading your lawn, you'll be sadden to learn to that there is no herbicide that only kills these grassy weeds that will not also kill the desirable lawn grasses.

Removal

Bentgrass is shallow-rooted. Patches appear as puffy, fine-textured grasses in Kentucky bluegrass lawns. You can remove patches of Bentgrass by cutting the patch out with a hand sod cutter or shovel. Cut down to at least one-inch deep. You will need to reseed the area.

Chemical control

The other method of controlling Creeping Bentgrass is to apply a herbicide that contains the active ingredient glyphosate. These herbicides are sold as Round Up or Kleen Up and that they will kill everything in the lawn including desirable grasses as well as weeds. Apply the herbicide only on the Bentgrass patches and plan on re-seeding the area..

Apply the herbicide to an area about 6" or so outside the patch of Bentgrass to kill the individual stems which are creeping outwards from the patch, otherwise, these patches will reemerge. Apply the glyphosate in spring or fall when the grasses are actively growing. Wait approximately 7 days, then reseed or sod the area. If you decide to till the soil prior to establishment, and see bits of quackgrass rhizomes coming to the surface, remove these or wait 2 weeks or so until enough new quackgrass leaves emerge and kill the new plants with a second application of glyphosate.

Bentgrass summary

  • Reproduces by seeds and stem pieces

  • Cool season perennial

  • Creeping bentgrass spreads by vigorous above-ground stems and forms puffy, dense patches of fine-textured grass capable of forcing out other turfgrasses

  • The blue-green leaves of creeping bentgrass are flat, about 1/8" wide and usually rough on the upper and lower sides. The tip is pointed and the veins on the upper surface are prominent

  • The purplish flowers of creeping bentgrass are compressed panicles usually occurring in late spring or early summer

  • Creeping bentgrass can occur in most lawns throughout the growing season, especially in moist fertile areas where turf grass is mown closely

  • Maintain a thick turf density and health through proper culture, avoid over watering, over fertilization and close mowing

  • Use a product such as Roundup to control creeping bentgrass during periods of active weed growth