Chinese/Oriental Clematis (Clematis orientalis L.)

Eradication of all live plants is required throughout the entirety of all Colorado counties.

• Perennial vine with solitary flowers with four yellow sepals (petal-like structures).
• Each flower produces numerous feathery long-tailed seed heads fruits which are conspicuous all winter.
• In Gilpin, Chinese clematis can be seen along side 119 coming up from Clear Creek Canyon.
• -Reproduces by seeds. In Gilpin County, it starts going to seed mid-July.
• -Prevent the spread of this species by eliminating seed production from established stands, and discontinuing its use as an ornamental. Hand pulling or weed whacking before it flowers and goes to seed will help keep seeds from spreading.

Control

• Mechanical:
  – Dig from moist soil, being certain to get all the roots
  – Bag specimens carefully so as to not scatter seeds if flowering. You may have to pull a few times over the season if it comes back from the root.

• Chemical:
  – 2,4-D amine or ester is the best recommendation for homeowners
  – Apply at flowering growth stage, 2 qt product/Acre
  – Caution – will kill other flowers and possibly trees; grass will not be harmed

CSU trials demonstrated that Weed-B-Gone 2,4-D (218 oz/A) controlled 78 or 80% of the Chinese Clematis.

No endorsement of this product implied, nor non-endorsement of products notmentioned.

The soil seed reserve of clematis is unknown so the site must be monitored for at least 10 years after the last flowering adult plants have been eradicated and treatments repeated when necessary.

Native look-alike: Western or White Virgin’s Bower Clematis

We do have several native Clematis which are NOT noxious weeds. One of these is a vigorous, sprawling vine which can sometimes be mistaken for Chinese Clematis– particularly when it’s not in flower. Western, or Virgin’s Bower Clematis, Clematis ligusticifolia, has white flowers, not yellow. After they have gone to seed, you can tell them apart by the fact that Chinese clematis has solitary, larger seed heads (golf ball size), and the Native clematis has clusters of 3 seed heads (ping pong ball size) somewhat like the tines of a fork). The native clematis can be valuable for erosion control and other ecosystem functions.

Photo credit: Gary A. Monroe @ USDA-NRCS PLANTS Database

For Further Information:
https://www.colorado.gov/pacific/agconservation/chinese-clematis