Asiatic Bittersweet (Celastrus orbiculatus)
As the name suggests, this plant is native to East Asia. It is thought that it was brought to America in the 1800’s as an ornamental plant, but by now it has spread to much of eastern North America. Asiatic bittersweet is a light to dark brown woody vine, with oval leaves showing pointed tips. Small bumps (lenticels) are noticeable on its branches. The vine forms large thickets on the ground when it does not find a surface to climb. However, when it finds surfaces such as trees, it will scale them. The vines will encircle and begin to strangle trees, while climbing up to known heights of 60 feet. These traits quickly cause problems for surrounding plants: on the ground it will choke out other ground vegetation, and by strangling trees it will slowly kill them.
In the winter, you can usually distinguish Asiatic bittersweet vines on trees from poison ivy and other vines by the tight circles that the bittersweet makes around the trees – often embedding itself in the bark of the growing tree. Poison ivy climbs more “vertically”, with small tentacle-like rootlets clinging to the tree bark to assist in the climbing process. Thus it rarely “strangles” a tree.
Full eradication of the plant at specific sites can take years of repeated cutting and coating with herbicide, which is best done at the first killing frost. This timing is the most effective for killing the plant. In addition, in the autumn, it is more easily distinguished from the native North American Bittersweet. Both have bright red berries that are revealed when yellow coverings split open in the fall. The American Bittersweet’s berries are all located on the end of each branch, where the Asiatic Bittersweet’s berries are located between the leaf and stem, more spread out along branches.