Weed of the Month: Cheatgrass Treatment

Invasive Species: Cheatgrass (Bromus tectorum L.)

Cheatgrass is an annual or winter annual invasive grass that can grow anywhere from 4-to-30 inches high with dense hairs on its leaf sheathes. Cheatgrass also has an early lifecycle which allows growing to begin immediately after the snow melts.

In Teton County, it begins to cure out by June, and by mid-June or July it has completely dried out. This aggressive, quick-growing life cycle not only gives it a competitive advantage over other plants and allows to completely choke out other native plants in the area.

Adding to cheatgrasses devastating qualities is the fact that it is only palatable in the early stages of the life cycle. Once past this stage, cheatgrass becomes an increasing fire hazard issue as it dries out and creates vast amounts of biomass/leaf litter.

Control Options

  • Small Patches: Hand-pulling
  • Spring Treatment (while green and before seeds are produced): Roundup
  • Fall Treatment: Laramie

Laramie Treatment Option

  • Active ingredient is rimsulfuron, which is in the same family of herbicides as Telar and Escort.
  • Previously sold as Matrix
  • Works by killing late season second wave plants and by preventing germination the following spring
  • When treating, apply to both the ground in and immediately around patches and growing cheatgrass directly with Laramie.
  • Must have an incorporating precipitation event within 3 weeks of application. Usually treatments can begin in late September and continue until snow starts to accumulate.