Mineral County Noxious Weed Program


What Are Noxious Weeds?

A weed is often defined as 'a plant out of place'. This simple definition can refer to any plant in any setting. A 'noxious weed' has a special definition with a legal connotation. The Mineral County Noxious Weed Control Program follows the guidelines of the Colorado State Noxious Weed Act which defines 'noxious' weeds as plants that are exotic, invasive and poisonous. Exotic means non-native, or weed species that originated in other parts of the world. Invasive plants are those vigorous enough and competitive enough to crowd out desirable native plants, and in doing so, decrease native plant diversity and wildlife habitat. The increased vigor and competitive ability of a non-native plant is the result of being introduced into a country without its natural controls, differences in grazing animals, predatory insects, disease and other limiting factors that kept the species in check in its native land. Noxious weeds also have the potential to harm livestock and wildlife by poisoning and by reducing native forage.

The Colorado State Noxious Weed Act lists 71 weed species considered to be a threat to the economy and environment of Colorado. Another 24 species are listed on the state's Watch List. The lists are categorized by priorities:

  • List A species are of the highest priority. These weeds are not well established in Colorado, are potentially a large problem to this state, and require mandatory eradication by local governing agencies.
  • List B species are species for which the Commissioner, in consultation with the state noxious weed advisory committee, local governments, and other interested parties, develops and implements state noxious weed management plans designed to stop the continued spread of these species.
  • List C species are species for which the Commissioner, in consultation with the state noxious weed advisory committee, local governments, and other interested parties, will develop and implement state noxious weed management plans designed to support the efforts of local governing bodies to facilitate more effective integrated weed management on private and public lands. The goal of such plans will not be to stop the continued spread of these species but to provide additional education, research, and biological control resources to jurisdictions that choose to require management of List C species.
  • Watch List are species which are on this list to educate and encourage identification and reporting. They are determined by:
    1. Not known to occur in the state but their noxious characteristics are found in the region.
    2. They have been found to display noxious characteristics in plant communities similar to those in Colorado.
    3. They have noxious characteristics as determined by the plant assessment process used by the state, yet their distribution and effect on lands in the state is still unknown.

The Mineral County Noxious Weed Management Plan requires eradication of all List A species, as mandated by the state, and containment and suppression measures for any of the List B species identified as significantly troublesome in Mineral County. County outreach programs emphasize education, identification and management of the List B species but the Noxious Weed Program reserves the right to enforce on any state-listed noxious weed if infestation size and density deems it necessary.

Additional noxious weed info can be found at the Colorado Department of Agriculture web site.

Noxious weeds have well developed and specialized mechanisms to survive and can spread at alarming rates.

  • Leafy Spurge seeds are expelled from their seed capsule and can fly up to 30 feet. Leafy Spurge contains a sap that may cause blisters in the mouth of cattle and wildlife. The animals will eat desirable vegetation but will leave the Leafy Spurge.
  • Houndstongue seeds have tiny hooks that attach to fur and clothing.
  • Diffuse Knapweed breaks off at the base and acts as tumbleweed. It is often found lodged in the underside of vehicles that have driven over the dried plants.
  • Eurasian Watermilfoil can easily be transported on fishing equipment.
  • Purple Loosestrife can produce 2-3 million seeds per plant every year.
  • Orange Hawkweed has developed hairy leaves that most animals will not eat.
  • Canada Thistle plant is 75% underground.

For more information please contact:

Andrew Marino
Noxious Weed Manager
P.O. Box 70
1201 N. Main St.
Creede, CO 81130