Most noxious weeds come from Europe or Asia. Seeds or plant fragments are unknowingly transported to new areas where they are spread and grow into plants. Many noxious weeds have been sold as ornamental plants that have escaped home gardens and spread into the wild.
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Noxious weeds are plants growing outside their natural habitat. These non-native plants become problems because they are invasive and can spread quickly in a variety of ways.
The state Noxious Weed List is divided into four categories.
Once you discover a noxious weed on your property, it is important to act. An integrated approach, including one or more control techniques, will provide the best chance for success. Remember, weed control is a process that requires patience and repeated efforts; what works to control one weed might not work on another. Review the Noxious Weed Information page for additional assistance.
The Colorado Noxious Weed Act (CRS 35-5.5) was passed in 1990 and updated in 2003. This law requires all public and private landowners in the state of Colorado to maintain control over certain noxious weeds. The law addresses the severe threat these non-native plants pose to native plant communities, wildlife habitat, agricultural lands and property values within the state.
Landowners that have noxious weeds on their property are required to control them.
Planning and Zoning is the department that handles tall weed complaints.
Noxious weeds are often pretty, but their effects are not. The absence of natural enemies in the new environment means weeds can spread uncontrollably, vastly reducing the number of native plants. This affects wildlife that depends on native plants for food; therefore, an increase in noxious weeds results in decreased native wildlife populations.