Weed management is performed through proactive and reactive measures to ensure alignment with City goals and state regulatory requirements. The City takes an Integrated Pest Management (IPM) approach to weed management and uses cultural, chemical, mechanical, and biological methods. Spraying herbicide is a normal part of ecological restoration practices and is one of the many methods City staff use to control certain weed species.
Weeds
The Colorado Department of Agriculture defines a native or introduced species as a noxious weed or one that causes harm to trail users or poses a threat to native plant species. For example, foxtail barley is native to Colorado plains and foothills. Still, City staff actively eradicate it at Rover Run Dog Park because it can harm dogs.
Introduced Species
A species that has been brought into an area in which it did not historically exist. An example of an introduced species in Colorado is kochia, one of the plants that produces tumbleweeds.
Noxious Weeds
Introduced plant species that have been designated as being noxious (unhealthy) by regulatory officials and meet one or more of the following criteria:
- Aggressively invades or is detrimental to economic crops or native plant communities
- Poisonous to livestock
- Carrier for damaging insects, diseases, or parasites
- Its presence has a direct or indirect effect on natural or agricultural systems
- An example of a noxious weed in Colorado is Canada Thistle.
Learn more about noxious weeds by visiting the Colorado Department of Agriculture website.
The Colorado Department of Agriculture organizes noxious weeds into categories. Weed management is regulated by the list designation of each species (see below).
- List A: Designated for eradication on all county, state, federal, and private lands.
- List B: Species whose continuous spread must be stopped. This could be through suppression or eradication.
- List C: Species recommended for management. The local governing body determines management.
Learn more about state rules around noxious weeds.
Prioritization of Managing Weeds
Because of state requirements, City staff prioritize addressing list A species first, followed by List B, C, and other weeds. Some examples of the list A species that City staff are required to eradicate include purple loosestrife and hairy willowherb.
City staff manage List C species, such as puncturevine, which grow near trail edges because they negatively impact trail users.
Some nuisance weeds, such as Kochia, do not even appear on these regulatory lists. As a result, they are managed as a lower priority than the species that the City is legally required to eradicate. City staff manage Kochia and Russian Thistle along trail edges through chemical application and mowing. Management of these species further from trail edges is dependent on staff availability.
If you encounter an area that needs attention, please click on the button to the right to fill out a report.