Northglenn parks staff present updated noxious-weeds management plan; council asks for outreach and follow-up

Parks staff presented an updated noxious-weeds management plan July 7 and asked the City Council for feedback before bringing a final draft back to the council on July 28.

Parks manager Willis Waterhouse told the council the plan has been substantially updated for 2025 to comply with the Colorado Noxious Weed Act and the city's local noxious-weeds ordinance and to document management priorities and methods. "The purpose of this plan is to provide an overview and seek some feedback regarding the proposed update to the noxious weeds management plan," Waterhouse said. He reviewed the plan's objectives, which include targeting species such as teasel, Canada thistle, musk and Scotch thistle, poison hemlock and hoary cress, and expanding biological controls and GIS mapping of infestations.

Waterhouse described the plan's seasonal management schedule: February sets biological-control selection; March'April is inspection for early emergents (poison hemlock, teasel); April'May begins spraying operations, including targeted applications and goat grazing; July continues spraying with weed-specific targets (e.g., napweed); August includes scouting for purple loosestrife and yellow toadflax. The presentation noted the program has eradicated all known purple loosestrife populations on city property and that goat grazing has been used as a control tool since 2023.

Council members asked several technical questions. Council member Kondo asked about "tree of heaven" (Ailanthus altissima); Waterhouse said the tree had previously been on the city's priority list but was removed and is addressed via the city's code-enforcement process: "If there are reports of the tree of heaven plants on any private property or public property, we will work directly with the code enforcement agency." He described the recommended multi-year treatment (stem injection/chemical treatment to kill the root system before cutting) and said the city relies on Colorado State University Extension literature for protocols.

Council member Nowicki asked about biological controls for bindweed and other species; Waterhouse said biological measures have been used but that results can take multiple years to produce substantial progress, and that Colorado State Extension has programs (aphid releases, for example) the city is monitoring. When asked about pollinator safety and herbicide choice, Waterhouse said the Butterfly Pavilion is collaborating on surveys and plantings and that staff attempts to reduce spray in pollinator-prone areas and to select appropriate control methods.

Staff told the council the parks and recreation advisory board recommended proceeding; Waterhouse said he would bring the finalized plan back on July 28 if council wanted to move forward. Council members voiced general support and asked staff for clearer visuals in the final packet (updated pictures of target species were already added to this year's draft). No formal vote was taken; the plan remains in the study/feedback stage pending council direction at the July 28 meeting.

Key operational notes in the plan include ongoing monitoring, mechanical and chemical treatments as appropriate by habitat type (mechanical in wetlands; mechanical/chemical in dryland), continued use and evaluation of the goat-grazing pilot, development of GIS mapping of infestations and continued coordination with Adams County and the state extension service.