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Weed and Pest Management

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Parks, Open Space and Trails

Integrated Pest Management Plan

Please note that the term "pest" applies to animals, insects and weeds. 

The City’s Integrated Pest Management Plan (IPMP) provides management guidelines that:

  • Implement the mandates of the Colorado Noxious Weed Act by creating a plan for the control of noxious weeds using integrated control methods.
  • Adhere to City Code.
  • Consider the environmental, economic, and social impacts of different control methods as related to our Sustainability Plan.
  • Protect visitor and applicator safety, water quality, non-target vegetation, federally protected endangered or threatened species, and local species of concern.
  • Reduce the spread of pests from City of Longmont properties to adjacent or downstream/downwind properties.

The City reviews the IPMP annually to consider new technology and methods for controlling pests.

View the complete Integrated Pest Management Plan >

Pesticide Application

Mosquito Control

For information on the City's mosquito control strategy, please visit our dedicated West Nile Virus webpage. 

Grass/Turf Management

Control of broad-leaf weeds (ex: dandelions) in grass/turf areas is done only as needed based on assessment thresholds established in complement to the City's Integrated Pest Management Plan. It is the City's goal to keep grass areas healthy so that weed growth is limited and does not require treatment.

Weed Control on City Property

The City of Longmont hires contractors each growing season to conduct weekly mowing operations. As part of this work, the contractors also check flowers beds, shrub beds, hardscapes, greenway beds, and all City maintained right of ways for weeds. If weeds are present, the contractors will spot spray in these areas. This is the most efficient way to control weeds and use the least amount of pesticide. Below is a link to the schedule for contracted mowing and weed control services.

Certain areas are treated more specifically during the growing season by our Natural Resources staff. They conduct spot treatments only as needed to eradicate a target species. Below is a link to their weekly schedule of planned activities.

Please note that all treatments are subject to change due to weather or other unforeseen activities.

The City and all contractors working for the City comply with the Colorado Pesticide Applicators Act and the Rules and Regulations Pertaining to the Administration and Enforcement of the Pesticide Applicators’ Act.

Spray Area Tips

  • Yellow flags are posted after each application; they will have the name and date of the application.
  • Please wait until the yellow flags have been removed before allowing kids and pets onto those areas. 

Contact Us

If you have questions, suggestions or concerns about the City's Integrated Pest Management Plan or pesticide application, please contact us via ServiceWorks.

  • Select Parks & Trails
  • Request Type - Parks: Pesticides (Herbicides & Insecticides)


Expand/Contract Questions and Answers

  • Does the City have a weed management plan?

  • Does the City have a Pollinator Plan or Policy?

  • What about glyphosate uses in Longmont?

  • What about pesticides that impact pollinators?

  • How can I discover where Longmont is spraying pesticides?

  • What pesticides are used in Longmont?

  • How does pesticide use in a City compare to agricultural or other commercial types of pesticide application?

  • How do you really know pesticides are not hazardous?

  • Are pesticides hazardous?

  • Why use pesticides to control weeds when other methods are available?

  • Why does Longmont eliminate some weeds that are not considered noxious?

  • Are weeds regulated in Longmont?

  • What is a weed and why do we control weeds in Longmont?

  • Why are pesticides used by City of Longmont?

  • Why doesn't the City spray for all dandelions?

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