Noxious Weeds

A serious and growing problem in the West is the invasion of aggressive, non-native plant species, commonly called noxious weeds. Noxious weed infestations degrade native plant communities (which provide valuable food and shelter for wildlife) and contribute to a loss of agriculture productivity. They also greatly disrupt the recreational enjoyment of our natural resources and have serious economical impacts associated with their management.

Noxious weeds are undesirable, exotic plant species that are detrimental to natural lands, wildlife habitat and the human uses of these resources. Noxious refers to the species' aggressive behavior, which damages native plant communities or economic crops. Because these species are outside their natural range, they no longer have predation. This allows them to adapt very successfully to our environment and gives them an advantage over native species. Noxious weeds outcompete native plants for food, space, light and nutrients and over time form unproductive monocultures that can not support the diverse wildlife the native species could support.

Noxious weeds enter our ecosystems by hitchhiking on people, animals, water, wind or vehicles. Weeds are also introduced by unsuspecting gardeners, hikers' shoelaces, pet fur, cars and equipment and as stowaways on planes, boats and even in luggage. There are many ways you can help prevent the spread of noxious weeds:

• Before entering or leaving a park, check your shoelaces, vehicles, bikes and pets for weed seed. 

• Clean your gear and prevent a noxious weed infestation from getting established in new places. 

• If you love to garden, plant native species! We have many beautiful native wildflowers in Colorado that create breathtaking gardens.

• Learn more about how you can help by visiting our Invasive Species Program pages.

Stewardship and Park Staff are hard at work controlling noxious weeds at every park and attempting to prevent new infestations from taking over. Prevention is key and we must always be on the look out for new invaders. Rapid response is our best defense!

For specific species information, please see our Species Profiles. For more noxious weed information, please see Links to other resources.

How are weeds controlled?

Noxious weed control methods are specific to the species and area being controlled. An integrated management plan utilizing all tools available is the most effective way to successfully control weeds. Control methods include:

• Education and Prevention

• Cultural: Materials or techniques, such as mulching or establishing good native communities, to control weeds

• Mechanical: Mowing, Hand-Pulling, Mechanical Removal

• Biological: Using organisms such as insects to control weeds

• Chemical: Using herbicides (according to their label) to control weeds

Colorado is seeing a dramatic increase in noxious weeds. Left uncontrolled, noxious weeds will form dense mono-cultures and displace native and desirable plants. Native plant loss affects wildlife that depends on the native vegetation for survival.

Please select from the following to find detailed information on the weed in which you’re interested.

~Colorado Parks & Wildlife; JeffCO.us