Larimer County designates meadow hawkweed a noxious weed with eradication goal

Larimer County commissioners voted Feb. 24 to add meadow hawkweed (Hieracium cespitosum) to the county’s noxious weed list and adopt eradication as the management goal.

Casey Cisneros, a Larimer County Weed District staff member, told the board meadow hawkweed is on the Colorado state watch list and currently occurs on four Larimer County parcels near the Boulder County line along Highway 7. Cisneros said staff coordinated with the Colorado Department of Agriculture’s weed management program and that treatment on one parcel produced substantial reduction after one year.

"As a noxious weed is present on the landscape, the longer it's on the landscape, the more costly it becomes," Cisneros said, explaining the staff rationale for early detection and rapid response. The Land Stewardship Advisory Board recommended adding the species to the county list with an eradication objective.

Commissioners discussed treatment methods. Cisneros said the Weed District uses integrated techniques — mowing, weed whipping, hand pulling and, where effective, biological controls — but that herbicide is the most efficient option for this deep‑rooted perennial; staff noted targeted, selective broadleaf herbicides were used and that broadcast applications had been followed by spot treatments the following year.

The board’s motion to add meadow hawkweed, made under the county’s authority and referencing Colorado Revised Statutes related to noxious weed management, passed 2–0. Staff said the designation directs land managers countywide to control the species and that the Weed District has been providing free treatment to affected private landowners to date.

Commissioners noted treatment would use minimal herbicide now because infestations are very limited, and that early action increases the chance of complete eradication.