"Oriental Bittersweet was once widely used at this time of year for seasonal decorations because of its very colorful berries. Hopefully all wreaths and ornaments made with this species of Bittersweet vine are now relegated to the history books because of the damage this plant does to ecosystems. It is illegal to sell, distribute, or transport it anywhere in Massachusetts," reminded Claudia Thompson, director of Grow Native Cambridge.
Oriental Bittersweet, Celastrus orbiculatus, is native to eastern Asia (Korea, China, and Japan). Brought to the United States for its ornamental "value," in the mid 1800s, this plant has now invaded the entire northeastern U.S., causing serious ecological damage to woodlands and forests throughout the region. Here in Massachusetts and elsewhere, it establishes relatively quickly and rapidly climbs up over trees and shrubs, monopolizing the tree canopy. The vine, which sometimes grows as large as 4-5" in diameter, twines around tree trunks, effectively strangling them. Reaching the high woodland canopy, Oriental Bittersweet smothers trees, blocking the light and air they need to survive. Both individual trees and larger forests with Bittersweet invasions are highly vulnerable to uprooting and blow-downs during storms.
Oriental Bittersweet is one of over 140 invasive and damaging plants now on the Massachusetts Prohibited Plant List, and it has been illegal to sell, transport, or propagate this plant since January 1, 2006. It means that it is against the law to collect this plant and its berries for use as ornaments or for any other purposes. It means that it is illegal for florists to sell wreaths made with Bittersweet. The objective is to prevent the spread of this plant further, since the berries so readily sprout and start new infestations.
We also highly recommend that you remove any Bittersweet from your property. When young, it looks like an innocent enough woody vine, often growing straight up from the ground because of its strong stem. If the plant is small, you can pull it or dig it with a bit of effort, and you will notice that its roots are quite orange. Plants reproduce vegetatively by suckering, in addition to spreading by seed, quickly becoming tangled masses. If you have large vines or infestations, you will need to cut them. And a responsible application of cut stem herbicide immediately afterward should prevent them from resprouting.
It is common to find infestations within our communities throughout Massachusetts. The good news is that, once identified, Bittersweet is one of the easier invasives to control if we take appropriate action.
And if you have loved Bittersweet for its ornamental value and are feeling blue about losing it for your holiday decorations, get some Ilex verticillata or Winterberry sprigs. Many responsible florists are selling these instead. This wonderful native plant has stems with beautiful red berries that make great wreaths and decorations.