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The Rio Grande Conservation District recognizes the harm that noxious weeds can cause to native plants and habitats. Therefore it presents the following information for land owner use.

A Rio Grande County Weed Species of Concern:

Mosca weeds

Habitats for Russian knapweed includes many land types, from roadsides, ditch banks, riparian zones, pastures, irrigated cropland, clear cuts, and cropland.

The most effective method of control for Russian knapweed is to prevent its establishment through proper land management. Maintain healthy pastures and rangeland and continually monitor your property for new infestations. If Russian knapweed is already established, using an integrated weed management approach proves to be effective. Russian knapweed can be managed with herbicides or insects, but long-term control must include planting competitive plant species to occupy bare ground once infested by the weed. Details on the back of this sheet can help to create a management plan compatible with your site ecology.

Russian knapweed is designated as a “List B” species on the Colorado Noxious Weed Act. It is required to be either eradicated, contained, or suppressed depending on the local infestations.

All noxious weeds are non-native species.  They become listed by the State weed advisory board as a noxious weed when it meets one or more of the following criteria:

  • Aggressively invades or is detrimental to economic crops or native plant communities.

  • Poisonous to livestock.

  • The direct or indirect effect of the presence of this plant is detrimental environmentally to natural or agricultural ecosystems.

All noxious weeds are invasive due to the lack of natural insects and disease to keep their populations in check.

See information about Colorado's Noxious Weed Management Program: