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  • Integrated Pest Management
  • Protecting Pollinators
  • Invasive Species
  • Reducing Pesticides
  • Mosquito Control Program
  • Natural Lawns and Landscaping

Removing Noxious Weeds From Your Property

Removing Noxious Weeds From Your Property

The State of Colorado has designated specific plants as weeds because the plants present a threat to natural lands, including Boulder's beautiful open spaces. Some of the plants that may be growing on your property are Myrtle Spurge, Japanese Knotweed and Purple Loosestrife. The Colorado Noxious Weed Act (35-5.5 CRS) prohibits these weeds on all property and requires local governments to enforce this law.

State-mandated Eradication of Specific Noxious Weeds on Private Property

In order to comply with the state regulations, the City of Boulder passed an ordinance change to its existing weed ordinance to require property owners to remove "List A" weeds from their properties. "List A" weed species, as provided in the Colorado Noxious Weed Act, are plants that have yet to be well-established in Colorado but are either present in small populations or are invasive in nearby states.

The proposed ordinance change was presented as a City Manager's Rule Change on May 3, 2013 in the Daily Camera. Public comment on the proposal was accepted until May 20, 2013.

As a result of the ordinance being approved, starting on June 1, 2013, the City of Boulder began an outreach and education effort to inform Boulder residents that these weeds must be removed from private property. Code enforcement officers provided information about how to identify and remove these weeds, as well suggestions for preventing the weeds from coming back and what to plant in their place. Information was also provided to gardening retailers and landscapers. Enforcement action will be pursued only as a last resort. Voluntary compliance is the goal.

Noxious Weed Removal and Control - What Should You Do?

As a Boulder resident, familiarize yourself with the noxious weeds in your area and monitor your property. The State of Colorado requires you to eradicate "List A" species from your own property. Start as soon as you see the weeds, as it will save time, money, and effort in the long run.

How to Remove Weeds

  • Mechanical control involves repeated pulling, cutting and covering.
  • Cultural control is intended to reduce noxious weed populations by providing an environment that discourages weed growth. Examples include establishing a good native vegetation cover, mulching and rotational grazing.
  • Biological control uses organisms, such as insects or fungal diseases, to control some noxious weeds. An example is the weevils that are used to control Goatshead or Puncturevine (Tribulus terrestris).

* Please do not compost noxious weeds as this will spread the weeds to other locations.

More Information

To better understand how ornamental plants become weeds and why they are considered a problem, review the background information provided on the Noxious Weed Ecology webpage.

For a full list of noxious weeds contact the Colorado Department of Agriculture at 303-239-4100.

Photo Gallery

Removing Noxious Weeds Photo Gallery

Myrtle Spurge - The King of NoxiousnessMyrtle Spurge - Colorado List A noxious weedIt escapes from people's gardens and becomes an invasive pest.Volunteers and staff on OSMP work very hard to remove Myrtle Spurge from the land.Myrtle Spurge - The King of NoxiousnessMyrtle Spurge going to seedPurge Your Spurge Event

See all related photos in the Photo Gallery

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