In some cases, annual weeds must be dug out, or simply tolerated. Mowing annual weeds frequently enough to prevent seed formation can reduce infestations substantially over time. The more common perennial grass weeds in Montana include quackgrass, orchardgrass, creeping bentgrass, and brome. To control these weeds, you will need to apply a non-selective herbicide such as Kleenup or Roundup. These products contain glyphosate, a least-toxic herbicide that is environmentally gentle when used as directed.
Some people wear rubber gloves and apply the product with a sponge.
The advantage of glyphosate is that it moves down into the plant and kills the root system, essential in the control of perennials. Digging perennials out by hand is often ineffective because they are usually deep-rooted and if the entire root system is not removed, new plants can grow back, actually worsening the problem. Be sure to read and follow label directions carefully when using any pesticide. Turfgrass Ecology and Management . Lajeunesse, S., G. Johnson, and J. Jacobsen.