Bittersweet (alias; Celastrus orbiculatus)
Oriental Bittersweet and Wisteria have similar characteristics. They both spiral up the trees and tighten around the trunk like a tourniquet, cutting off the flow of nutrients and strangling the tree.
Under the protective bark of a tree is the inner bark, or “phloem.” This is the pipeline through which food is passed to the rest of the tree. Just under that is the “cambium” layer, the growing part of the trunk. These layers are critical to the life of the tree. And it is right here that Bittersweet strangles and kills its victim.
Bittersweet has berries and rounded oblong, serrated leaves, while Wisteria has pointed, ruffled, serrated leaves. Oriental Bittersweet reproduces by seed and rhizome. The seeds are consumed and dispersed by birds and deer. The ingested seeds have a higher germination rate than seeds that fall to the ground.
Many people have been seduced by Bittersweet because it has semi-fragrant flowers and attractive orange and red berries in the early winter. Do not succumb to its charms; it’s a killer and it spreads fast. We take out a lot of Bittersweet!
We have seen entire woods completely consumed by Bittersweet. In addition to robbing trees of surface water and nutrients, the added weight of the vines covered with snow and ice can break off trees and shrubs. Oriental bittersweet outcompetes and displaces our indigenous American Bittersweet.
Eradication: Bittersweet is much easier to eradicate than Wisteria. The bright orange roots are easily identifiable. They are tiny but there are a lot of them and they pull out fairly easily. We have very good success with getting it out, and we surely don’t mind their root beer smell in the early summer.
Like Grape, we’ll get it off the branches if possible. It’s a real climber though, and usually it will have to die up on the tree.
As with most invasives, keeping Bittersweet away will require a maintenance plan. We’ll give you some options for that. Don’t worry, the big investment is the first effort.
Thereafter, it is much quicker and easier to stay on top of it.