Noxious Weed Management Program

• What is a noxious weed?

  According to the Colorado Noxious Weed Act, a noxious weed is an alien plant or parts of an alien plant that have been designated by rule as being noxious or has been declared a noxious weed by a local advisory board, and meets one or more of the following criteria:
  a) Aggressively invades or is detrimental to economic crops or native plant communities;
  b) Is poisonous to livestock;
  c) Is a carrier of detrimental insects, diseases, or parasites;
  d) The direct or indirect effect of the presence of this plant is detrimental to the environmentally sound management of natural or agricultural ecosystems.

   

   

• Why should residents and visitors to Colorado care about noxious weeds?

  Noxious weeds threaten valuable wildlife habitat and natural resources, cause economic hardships to agricultural producers, and are a nuisance for recreational activities. The Noxious Weed Act requires all Colorado residents to control noxious weeds using integrated methods to manage noxious weeds if the same are likely to be materially damaging to the land of neighboring landowners.
  

• What are the designated noxious weeds in Colorado?

  Colorado's noxious weed list is separated into three categories; list A, B, and C. We are currently developing a fourth category, a “Watch List,” for species that may be considered noxious in Colorado once more is known about the biology and behavior of the plant.
  Colorado Noxious Weed List.

   

• Whom should I contact if I see a noxious weed or unknown weed on my property?

  Contact your County Weed Manager, Colorado State University Extension office, or Conservation District. They will be able to confirm the species of the plant and give you an idea of how to treat it. If it's a List A or List B noxious weed, they will report it to the Noxious Weed Program; if it's a List C species, the county may have resources to help treat the more serious infestations.
  Contact information for your local County Weed Manager.

• How can I obtain a copy of Noxious Weeds of Colorado?

  Copies are sold through the Colorado Weed Management Association or your county weed manager may have a copy of this guide. CWMA can be contacted at the following website www.cwma.org. The 2009 edition is currently available.

• How can noxious weeds be controlled?

  There is no one best way to rid the state of noxious weeds. Weeds, like all plants vary in how they reproduce, have varying root structures (extensive root systems or a single taproot), and how they respond to herbicides. That's why an integrated weed management (IWM) approach is necessary. This approach assesses the best techniques for a given species, from a choice of manual (mowing, pulling, digging up), cultural (land management practices such as irrigation, cultivation, types of cover or crops), biological (using plant pests that are native to the source of the weed; for more information on this visit our Biological Pest Control Program), or chemical (herbicides). Other tools and techniques can be used on larger, woody weeds such as Russian olive and tamarisk.