Weed Management

A major component of the Undesirable Plant Management Plan is the requirement to provide Douglas County Property Owners with technical assistance in determining methods to control or eliminate their weed problems.  Staff continues to insure County owned properties are under treatment for weeds, as well as working with other public entities to assist them in their weed control problems.  

Prevention, eradication and control are three general weed management strategies.   Be a good neighbor and control your noxious weeds.


What We Do

  • Develop and administer the Douglas County Noxious Weed Management Program including application of herbicides, mowing activities in County right-of-ways and County open space.
  • Provide weed management education to Douglas County citizens.
  • In conjunction with Tri-County Health Department, administer the Douglas County mosquito mitigation program through trapping for adult mosquitoes and larviciding immature mosquitoes in standing water bodies in Douglas County maintained properties and culverts.

Noxious Weeds in Douglas County

In December of 1991, the Douglas County Board of County Commissioners adopted an Undesirable Plant Management Plan in accordance with the requirements of Colorado state law, Colorado Noxious Weed Act, §35-5.5-101-119, C.R.S. The County provides a complete listing of identified noxious weeds in the Undesirable Plant Management Plan.

Douglas County utilizes integrated weed management techniques to combat noxious weeds. These techniques include biological control, hand pulling, revegetation to include use of competing grass seed mixes and herbicides. The County program places strong emphasis on education. As part of our ongoing effort, the County provides informational flyers detailing biology and control measures for many of the noxious weeds on the undesirable plant management plan.

Bull thistleBull thistle
Cirsium vulgare
Canada thistleCanada thistle
Cirsium arvense
Common mulleinCommon mullein
Verbascum thapsus
Common tansyCommon tansy
Tanacetum vulgare
Common teaselCommon teasel
Dipsacus fullonum
Cutleaf teaselCutleaf teasel
Dipsacus laciniatus
Cypress spurgeCypress spurge
Euphorbia cyparissias
Dalmatian toadflaxDalmatian toadflax
Linaria dalmatica & genistifolia
Diffuse knapweedDiffuse knapweed
Centaurea diffusa
Field bindweedField bindweed
Convolvulus arvensis
Hoary cressHoary cress
Cardaria draba
Cynoglossum officinale
Leafy spurgeLeafy spurge
Euphorbia esula
Mediterranean sageMediterranean sage
Salvia aethiopis
Musk thistleMusk thistle
Carduus nutans
Myrtle spurgeMyrtle spurge
Euphorbia myrsinites
Orange hawkweedOrange hawkweed
Hieracium aurantiacum
Perennial pepperweedPerennial pepperweed
Lepidium latifolium
Plumless thistlePlumeless thistle
Carduus acanthoides
Poison hemlockPoison hemlock
Conium maculatum
Puncturevine © Eric Coombs @ OR Dept of AgPuncturevine
Tribulus terrestris
Purple loosestrifePurple loosestrife
Lythrum salicaria
Redstem filareeRedstem filaree
Erodium cicutarium
Russian knapweedRussian knapweed
Acroptilon repens
Russian oliveRussian-olive
Elaeagnus angustifolia
Salt cedar
Tamarix chinensis,
T. parviflora, and
T. ramosissima
Scotch thistleScotch thistle
Onopordum acanthium
Spotted knapweedSpotted knapweed
Centaurea maculosa
Sulfur cinquefoilSulfur cinquefoil
Potentilla recta


More Information

For more information on weed management visit the Colorado State University Cooperative Extension [Natural Resources].

For specific control measures in unincorporated Douglas County areas contact Jonathan Rife, weed inspector at 303.660.7480.

For incorporated areas contact one of the Master Gardeners at the Douglas County Extension Office at 410 Fairgrounds Road, Castle Rock, 720.733.6935.

For help with pasture management, call the Douglas County Natural Resource Service and Soil Conservation District at 303.688.3042.

Additional Resources

Natural Resources - Board Goal

Online Services:

Weed Management

Public Works Operations Division

3030 North Industrial Way
P.O. Box 1390
Castle Rock, CO 80109
Phone: 303.660.7480
Fax: 303.814.3319

Office Hours

8:00 a.m. - 5:00 p.m.