Weed of the Month
Myrtle spurge is a List A noxious weed commonly found in the urban and foothill areas of Colorado. Initially sold as a xeriscape plant, this perennial of the spurge family, has escaped and naturalized in many areas including some remote and rugged areas.
Myrtle spurge shows up in early spring at lower elevations and begins to flower in March-April.
Grey-green leaves are fleshy, egg-shaped, and attach directly to the stem at their base. Stems are stout and trail along the ground. Leaves and stems contain a sticky, caustic sap that can cause severe rashes and blistering.
The inconspicuous flowers are surrounded by chartreuse bracts and develop at the ends of the stems. When the seeds ripen, they are expelled from their capsule and are covered in a sticky gel that adheres the seeds to surfaces and passing animals.
Landowners are encouraged to start looking for this plant in mid-February. It can be pulled as long as you remove the top few inches of the taproot. Herbicides also work well. The Colorado Department of Agriculture’s website has factsheets detailing control methods.
Cheatgrass is a winter annual grass that emerges in the fall and/or early spring. It has shallow fibrous roots and reproduces solely by seed. Seedlings are dark green and may be seen growing through previous years’ thatch. Mature plants can reach 20+ inches high but most plants are about 12 inches tall. Older plants are straw to red colored.
It can be found on all continents except Antarctica. It was introduced to North America in the mid-1800’s from Eurasia and was first noted in Colorado in 1892.
Cheatgrass matures earlier than native perennial grasses and its shallow roots utilize soil moisture and nutrients before deeper rooted plants can access them.
Cheatgrass burns hotter, quicker and more frequently than our native grasslands. The change in regime makes it harder for native grasslands to recover, making them even more susceptible to cheatgrass invasion.
Removal, grazing, or chemical treatment prior to any seed development are recommended controls. See the Cheatgrass Management Handbook: Managing an invasive annual grass in the Rocky Mountain Region for more information.