Boxborough Invasive Focus: Oriental Bittersweet
I didn’t have to go far to get pictures of this invasive species – I’d long suspected the tendrils at the side of my driveway, reaching up to grab the lower branches of my trees, was bittersweet. The benefit of getting it early is that it’s easy to pull the plant along with its roots. In winter it’s often simple to spot as it has the pretty red and yellow berries along the vine (American bittersweet, a rare non-invasive that’s threatened by the spread of the oriental version, has berries just at the tip). Don’t confuse poison ivy for bittersweet – PI has thick, hairy stems.
It’s not so easy once it gets hold of a tree. Earlier this year the Crown Castle company volunteered a huge number of their employees to help cut the bittersweet that’s taken hold of many of the trees on the north side of Steele Farm. Once established, bittersweet can choke a tree and eventually kill it.
Eradication can be a multi-year effort. Pulling roots is the best option, but even small parts left in the ground can regrow. Cutting the vine can at least temporarily relieve the tree, but it will regrow quickly without continued work. Herbicides can be used on cut stems and foliage. Search on Google for advice on this.