The City of Louisville uses an Integrated Weed Management Plan (IWMP) to control weeds in City-maintained parks including the sports complex, community and neighborhood parks, parkways, greenbelts, cemetery, and facility grounds. Weed control efforts employ a combination of prevention, monitoring, education, cultural control, mechanical control, and chemical control methods.

Park staff primary uses mechanical control methods such as mowing and hand pulling. However, chemical control, or the use of herbicides to eradicate weeds, is used on an as-needed basis in selective areas. By using an integrative weed management program, weed control is more effective and chemical applications are minimized. Spot spraying is conducted on an as-needed basis for weeds in areas such as shrub beds, cracks in concrete, and baseball infields.

In 2020, the City of Louisville discontinued the use of glyphosate and 2,4-D in City-maintained parks and Open Space, excluding Coal Creek Golf Course. Glyphosate and 2,4-D are synthetic herbicides used to control a variety of weeds. The City made the decision to discontinue using these two herbicides in response to public concerns regarding the use of these chemicals in areas that children, adults, pets, and wildlife frequent. This decision does not apply to privately owned property, City properties that are privately maintained, or jointly owned open space lands.

You can expect the following:

• You will see more weeds.
  More weeds, such as dandelions, may be noticeable, especially in rock beds, shrub beds, turf, and medians as our new approach will be less effective than the chemical applications used previously.
• You will still see spraying.
  Chemical control will continue to be used as a weed management tool in City-maintained parks, but will no longer include the use of synthetic herbicides including glyphosate and 2,4-D

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Herbicide Application

• When herbicides are need, staff uses organic substitutes when possible. Herbicides are applied using methods that decrease non-target exposure and off-site movement.
• If required, applicators employed or contracted by the City are either licensed or monitored by Qualified Supervisors licensed by the Colorado Department of Agriculture as pesticide applicators.
• Chemicals are applied following the City’s newly updated policies and all applicable state and federal guidelines.
• For questions or more information regarding herbicide application in parks, contact Abby McNeal at 303-335-4774 or AMcNeal@LouisvilleCO.gov

Helpful Links

• Boulder County Weed Management Plan