Noxious Weeds – Open Space Management


Noxious weeds are non-native species that were often introduced as ornamentals that then spread into natural areas and crowd out native species.  The vast majority of noxious weeds are non-edible to deer, elk, and rabbits and essentially destroy their habitat.

The various species are best managed as they emerge and before flowering.  If plants have gone to seed we are required to remove and bag the seeds and then spray or remove the parent plant.

The most common early season noxious weeds in the Willow Springs Open Space are scotch and musk thistles, mullein, poison hemlock, toadflax, houndstongue and myrtle spurge.  Common late summer weeds are Canada thistle, burdock, chicory and knapweed.  Many of these weeds are bi-annual and have a taproot, making pulling easy and effective.  Myrtle spurge and hemlock are caustic and require skin protection if handled.

All property owners in Colorado are required to comply with the Noxious Weed Act.   Jefferson County further refines the state weed lists to address particularly invasive species in our county.  The Jefferson County general Noxious Weed page can be found here.  They also have great information on weed identification and control, some of which is duplicated below as it applies to our Open Space.

Weed control volunteers are needed throughout the season, but especially in the spring when the soil is damp and pulling weeds is most effective.  If you can spend as little as a few hours just one time, we can use your help.  Please contact Kathleen and Steve, the weed czars, at to volunteer.

HYPERLINKS to Jeffco Data Sheets

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