Longmont, CO Invasive Plant Rules: Prohibited Species (2026)
Key Facts
- Named species
- Ragweed, thistle, knapweed, bindweed, dandelion
- State list
- CO Noxious Weed Act Types A-C
- Type A deadline
- 10 days after notice
- Fine range
- $50 to $500 per violation
Summary
Longmont declares ragweed, thistle, knapweed, bindweed, dandelion and any state-listed Type A, B or C noxious weed a public nuisance on any lot in the city, and § 9.32.010 requires the owner to remove them.
Any weeds, such as ragweed, thistle, knapweed, bindweed, dandelion or any Type A, B or C list noxious weeds, as classified by the state Noxious Weed Act (C.R.S. § 35-5.5-101 et seq), found growing in any lot or tract of land in the city, are a public nuisance and shall be removed.B.It is unlawful for any person owning or having possession of any land, including any abutting the public right-of-way, to permit any weeds, grasses or other unsightly vegetation to grow in height exceeding 12 inches or to otherwise become a nuisance. For purposes of this section, the term "public right-of-way" means and includes the nontraveled portion of any street or alley. The following are exempt from the height limitation of this subsection: vegetation intended to enhance the natural settings on city golf courses, primary greenways, trails, and parks; and production crops on agricultural properties. (Code 1993, § 9.32.010; Code 2009, § 9.32.010; Ord. No. O-92-27, § 1; Ord. No. O-2005-91, § 1)
Full Breakdown
Municipal Code § 9.32.010.A names specific nuisance weeds and folds in Colorado's Noxious Weed Act classifications (C.R.S. § 35-5.5-101 et seq.), covering any lot or tract of land in the city. Enforcement runs through § 9.32.020: the city sends written notice, and the owner or occupant must eradicate any Type A list species within ten days of mailing, eradicate meaning to permanently eliminate the species or population, not just cut it back. Ignoring the notice lets the city remove the weeds itself and bill the owner, with costs certified as a lien on the property.
Violations & Fines
Municipal court fines run $50 to $500 per § 9.32.060; a second conviction within 12 months carries a mandatory $100 minimum fine the court cannot suspend.
Frequently Asked Questions
What's the fastest deadline under this rule?
Does a second violation cost more?
Sources & Official References
Other rules in Longmont
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Prohibited Species in Nearby Cities
How other cities in Boulder County handle prohibited species.