Boulder, Colorado

Boulder, Colorado

The City of Boulder, Colorado is situated on the eastern slopes of the Rockies and has a somewhat similar climate and ecosystem to Calgary - cool and dry.

Thank you to the City of Boulder - Environmental Affairs Department for the following information from their web-site:

The City of Boulder manages nearly 30,000 acres of land in the Boulder Valley, along with numerous buildings and facilities. Every year, action is required in some areas to control noxious weeds and insect and animal pest populations. In 1993 the City of Boulder adopted an Integrated Pest Management policy to make city pest control operations more effective and less toxic. The IPM policy dictates that cultural, mechanical or biological controls be considered before using pesticides. Pesticides are only used as a last resort.

Types of controls

Cultural controls eliminate conditions favorable to pests. Tactics include improving and amending the soil; choosing hardy, native plants for landscaping; mowing; maintaining clean sites and good water management.

Mechanical controls eliminate pests by physically removing them. Examples include hand-picking or rinsing (with water) insects off garden plants, or using an old-fashioned mousetrap in your home.

Biological controls use other organisms to eliminate problem pests. Applying ladybugs to plats infested with aphids is a biological control.

Chemical controls include pesticides. Pesticides are potentially hazardous and should be used with extreme care.

What the City of Boulder is Doing

Open Space and Mountain Parks use controlled burning to restore natural conditions (controlling disease, exotic plants and insect pests); mowing and grazing to limit the spread of weeds; and the release of beneficial insects to control pest populations.

Public works plants medians with native vegetation; xeriscapes (low water use landscaping); and hand pulls weeds instead of spraying.

Parks and Recreation has increased the blade height for mowers, aerates turf and uses computerized watering to increase the vigor of grasses on city property. These activities limit the number of weeds and the need for herbicides.

The Forestry division treats trees only for those diseases and insect pests which potentially threaten the life of the tree. Non-toxic insect traps and other alternative products are used for tree care.

The Housing Authority, in conjunction with the city, is working with residents to reduce conditions favorable to pests; and testing products with lower levels of toxic chemicals.

The following section is written by the Coalition for a Healthy Calgary.

Natural Controls for West Nile Virus

The City of Boulder has identified that only two of the fifty-four species of mosquito in Colorado carry the West Nile Virus. To have effective control of these mosquito species “while mimimizing impacts to health and the environment,” the City monitors potential mosquito breeding sites from May to September.  On sites where the two mosquito species are found,  a natural bacterium (Bacillus thuringensis israelensis - Bti), is applied.  The bacterium attacks and kills the mosquito larvae. This limits the “possible future need” for pesticide fogging or spraying of adult mosquitoes. (1)

Note: The City of Calgary has a policy to use Bacillus thuringensis israelensis on mosquito breeding areas too.

The City also has adult mosquito traps around the City. If an adult mosquito was found that carried West Nile Virus, the City would consider using targeted spraying or pesticides. (2)


1)  “West Nile Virus Mosquito Management Plan” under Environmental Affairs section.  City of Boulder web-site.
2) “West Nile Virus” under Environmental Affairs section.  City of Boulder web-site.

Click here for actions you can take to support a pesticide bylaw.

Click here for how to use natural landscaping in your yard.