ST. PAUL, Minn. - As Minnesotans deck their halls this holiday season, the Minnesota Department of Agriculture (MDA) is asking them to watch for Oriental bittersweet - an invasive imposter easily mistaken for a common decorative holiday vine called American bittersweet.
Oriental bittersweet is established in many eastern states, and in 2010 was found in Winona and the Twin Cities. The vine is sometimes collected for use in wreaths and other decorative arrangements due to its bright fruit. However, this attractive indoor garland turns ugly in a forest environment by strangling and smothering trees. When established, it can dominate the forest canopy, reduce forest productivity, and block sunlight from understory plants.
"Oriental bittersweet is considered a serious threat to our forests based on what it has done in eastern states," said MDA Invasive Plant Specialist Monika Chandler. "You don't want this vine on your property if you can avoid it, so be wary if that bittersweet you're using to decorate this season has fruit capsules that are yellow instead of orange."
Oriental bittersweet plants spread when people unwittingly transport the vines or seeds, or even plant them on their property, mistaking them for the desirable native and non-invasive American bittersweet. While American and Oriental bittersweets have red fruit and look very similar, they are easy to distinguish in winter by the color of their fruit capsules, which surround the red fruit. American bittersweet has orange fruit capsules, while Oriental bittersweet has yellow fruit capsules.
The Minnesota Department of Transportation has detected Oriental bittersweet infestations on rights of way in Anoka, Dakota, Hennepin, and Ramsey Counties. In addition, a large infestation was discovered recently in Winona. To help prevent the spread of this nasty vine, MDA is asking Minnesotans who find Oriental bittersweet in holiday decorations to bag or burn the materials. Minnesotans who believe they have found Oriental bittersweet infestations can contact MDA's Arrest the Pest Hotline at 651-201-6684 or 1-888-545-6684. Potential detections can also be reported to MDA staff by email at Arrest.the.Pest@state.mn.us .
