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Gardening Articles

Weed Management

by EGC Weed Committee



Time to get your weed management program outlined and acted upon!


Each year schoolteachers teach thousands of children about native plants and ecosystems and yet as adults many people fail to understand how the diversity of native plants are being threatened in the foothills, the mountains, and the plains.


Today Jefferson County like most counties in Colorado is struggling against invasive non-native (noxious) plants which destroy habitat for wildlife and often are poisonous to livestock. Increasingly noxious plants decrease the biological diversity of an area. In total, weeds can significantly decrease land values for homeowners. Weeds are superior competitors for light, water, and nutrients. Many like knapweed produce a chemical toxin into the soil thereby making seed germination impossible for other plants. Disturbed soils from a building site, or an overgrazed meadowland or an increased area of weed growth all reduce the native grasses and forbs used by deer and elk.


There is growing attention to the problem of weeds and we in the garden club can readily volunteer our services helping others in our neighborhoods to identify and plan a control strategy. As many of us know, the noxious weeds here may never be eradicated because they are too tenacious and aggressive, but there are plenty of things we can do. Discuss and educate others by doing some of the following:

  1. Identify the weeds growing in your neighborhood.

  2. Inventory the type and amount of the weed(s).

  3. Know the available resources and tools appropriate for specific weeds.

  4. Determine which weed control method for use tailored to the weed and situation.

  5. Choose a weed control method to reduce weeds to an acceptable level that causes the least harm to people and to the environment.

  6. Impress upon people this ought to be a concerted effort for the neighborhood for it to be effective. Suggest to your homeowners that Weed Management be a board position.

The most effective management plan is an integrated one. Professional management includes all of these four methods:

  • Mechanical - Mowing, Hand-Pulling or Burning.

  • Chemical Application - Herbicides like Curtail, Tordon, Round-up, Banvel  Be sure to follow application rates. Extensive research and testing have gone into these suggested rates and more is not better. Many of these chemicals are so potent that they must be applied with caution and by a licensed operator.

  • Cultural - Grazing by Sheep and Cashmere Goats - This is an up and coming method. Goats are being used successfully in Wyoming and in Montana. If you know of anyone who rents goats, be sure to have the goat grazing done before the weeds go to seed !  Revegetation using Native Grasses - Any serious chemical treatment of an area must be followed with seed planting. Jefferson Soil Conservation District provides seed for the foothills ecosystem. Its Front Range Mix is made up of all native species and sells for $9.95/lb. There is free grass seed available for high country meadows, but you should call Gene Bahehouse and discuss with him your planned planting area. Several local stores sell grass seed mixes. Avoid the smooth brome seed, crested wheatgrass, annual rye, and Kentucky bluegrass.

  • Biological - Insects who feed on leaves, roots, and flowers are being cultivated to control weeds in areas that are remote and unlikely sites for chemical or cultural methods.  The Colorado Insectary is located in Palisade Colorado. (970) 464-7916.  This year biological control will be used at Alderfer-Three Sisters and Matthews/Winters Open Space Parks.

The most common of the noxious weeds are Musk and Canada Thistle, Knapweeds – Spotted, Russian, and Diffuse, Leafy Spurge, Purple Loosestrife…and a weed to watch Common and Mediterranean Toadflax.

Attention in late May and early June then at two week intervals during the growing season will shock root systems regardless of your method of control. Then in the early fall say late August or early September a second application of an herbicide will continue the control. If your neighbors are not convinced of the undesirability of a weed, urge them to cut off the flower heads as soon as they go to seed. Butterflies and hummingbirds feed on thistle flowers and these are important links to keep, so after the flower has set the seed then cut the flowers off. It is very important to bag the seed heads of all weeds a by putting them into a black plastic trash bag in the sun where the seeds ‘cook’ and this destroys much viability. A musk thistle seed can be viable in the soil for as long as 14 years…there are probably weeds out there now trying to beat that record !


Excellent on-line sources useful for education, quality and relevance:

If you need more information, call Alicia Doran, Jefferson County Weed and Pest Management Specialist (303.271.5989).

There are no quick fixes to eradicating weeds. Many weed seeds remain viable in the soil for years. The changing conditions of water, temperature, and light influence the yearly germination rates. Too little water for one will be the ideal water for another. Annually, two or three management methods must be used if weeds are going to be controlled.

“Wildflowers and native plants are as much a part of our national heritage as Old Faithful or the Capitol Building, but the world in which they once flourished is now disappearing.” - Lady Bird Johnson

Native plants create habitat, conserve water, and foster a sense of connection to our natural world. If we can count on all of us together then we too can create a more beautiful environment.

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