Search

Oriental Bittersweet: Invasion via Holiday Decoration

What is Oriental Bittersweet?

Oriental bittersweet (Celastrus orbiculatus), also known as Asian bittersweet, is an invasive, woody vine that is native to China, Korea, and Japan. The plant was introduced to North America as an ornamental in the 1860’s. Despite being on the Minnesota Noxious Weed List and Wisconsin’s NR40 Invasive Species list, Oriental bittersweet is still often sold in holiday arrangements due to its beautiful red berries.


Oriental Bittersweet in Fall

Photo Credit: MN Dept of Ag


Identification

Oriental bittersweet is most easily identified during the fall months when its green berry changes to red with a yellow capsule. Oriental bittersweet grows vines up to 66’ long and have alternating green oblong leaves with rounded teeth. It is also important to note that oriental bittersweet has separate male and female plants, and that plants flower in the spring with small, green flowers that have 5 petals.


Oriental Bittersweet vs. American Bittersweet

American Bittersweet is a native species to WI and MN. The main method of differentiation between it and the invasive Oriental bittersweet is that the flowers and berries of American bittersweet grow on the ends of the branches, whereas the flowers and berries of Oriental bittersweet grow on the leaf axis (seen below).


Oriental Bittersweet (left) vs. American Bittersweet (right)

Photo Credit: MN Dept of Ag


Why is Oriental Bittersweet Bad?

Oriental bittersweet is considered invasive due to its ability to girdle other trees and shrubs, consequently killing them. Because of this ability, Oriental bittersweet is easily able to outcompete native plants, including the native American bittersweet.


Oriental Bittersweet vine wrapping around a tree

Photo Credit: Rebecca Finneran, MSU Extension


How to Prevent the Spread

To stop the invasion of Oriental bittersweet, especially during the holiday season, avoid purchasing holiday arrangements with unknown berries. Additionally, never cut stems for DIY holiday arrangements without properly identifying the plant first. Inform your family and friends as well, and encourage them to do their research before buying their holiday decorations.


For More information on Oriental Bittersweet identification or removal, visit:

9 views0 comments

Recent Posts

See All