Weeds infesting plots of monkey grass can be pulled out by hand or eliminated with spot use herbicide solutions. In addition, preventative measures can be taken before planting monkey grass, which may significantly reduce weed encroachment.
Herbicides that work best when dealing with weeds in monkey grass are Envoy, Image and Segment. In most cases, a surfactant should be applied along with the herbicide. A surfactant is a soluble compound that, when applied to a weed, helps the herbicide stick to the leaves of the weed rather than simply dripping off. Not only does this help the herbicide kill the weed, it also helps diminish collateral application to the surrounding monkey grass.
Take preventative measures and prepare the area before planting the monkey grass. This reduces the possibility of weeds taking root. This can be done by covering the area with a broad application of herbicide, like Roundup or Finale. This eliminates all of the vegetation and gives the monkey grass a sterile bed of soil in which to grow. In addition to the broad herbicide treatment, Nitrogen should be applied in the amount of one pound per 1,000 square feet and rotated into the soil before planting the monkey grass.