Noxious weeds are species of plants that have arrived from other places on earth and have found our area to their liking. Once here, and without plant diseases, insects and animals to keep their numbers under control, they can out-compete our native and desirable plants by massive seed production, rapid growth, drought tolerance, rhizomatous growth patterns, and just plain not being very picky about where they grow.
Unfortunately, Colorado is host to invasive plants from all over the world. Oxeye daisy, Canada thistle and yellow toadflax (locally known as the high country three) are from Europe, tamarisk from Asia, Russian olive trees from Russia, and the list goes on. These represent only part of a list of hundreds of species from all over the globe. Some have become so common that they are now accepted as part of our lives forever. Dandelions are present in all but the best groomed lawns, hardly getting a nod from even the most fervent of weed warriors, who rightly assume that the potential to eradicate dandelions is non-existent.
Other invaders are common in specific parts of the region but are not yet present throughout. Whitetop, also known as hoary cress, is common on Wright’s Mesa where it will soon turn many fields white with flowers while sucking up precious spring moisture and nutrients that would otherwise nourish grasses and desirable plants throughout the season. Battling whitetop on Wright’s Mesa is difficult but not impossible; preventing it from spreading to new areas and removing it when it does spread is most important. Preventing a weed invasion is preferable to controlling one, thus, whitetop that is invading near Telluride or Mountain Village is a critical problem.
Still other invaders are new to the area, the region and even the state. Ouray County has an isolated invasion of meadow knapweed that may still be eradicated while the Norwood area has a similarly, uncommon, isolated infestation of sulfur cinquefoil that may yet be prevented from spreading area wide. It is critical that we recognize these uncommon invaders while they are present in isolated areas and in small populations. When new invaders are recognized early and control efforts are started immediately there is a good chance that landowners and managers, often in partnership with the county weed control programs, can prevent the next widespread, impossible-to-eradicate problem.
This year’s war on weeds is getting ready to kick into high gear. The annual blue mustard will bloom soon (it’s an annual; you can pull it before it makes seed and get rid of it). Those little tiny yellow flowers growing close to the ground in dry spots are bur buttercup – they will soon turn into hard, spiky little seeds that hurt when you step on them. Rake them up and throw them away.
Whitetop will make its appearance in the next few weeks. It’s time to think about what your control strategy will be. There is one sure truth about perennial noxious weeds – they will not go away on their own! You can’t starve them or water them to death. You can’t ignore them into disappearing. Arm yourself with information and plan to spend some sweat equity – isn’t your land worth it? Contact your county weed control program or CSU Extension office and go to war.
Sheila Grother is Weed Control Program Manager for San Miguel County.