How to Control Invasive Bittersweet | Gardening Advice
What can I do to manage the bittersweet entangling the bank at the back of my house and climbing the bushes and pine trees? I’m 87 years old, and it’s hard to get at it. — Mrs. A, Ludlow, MA
Oriental bittersweet (Celastrus orbiculatus) is an invasive vine that’s become a serious threat to some of our natural habitats in New England. Although each plant is relatively easy to control individually, the species produces profuse suckers and countless seedlings that make management a challenge. Get some professional help to control your established vines. Because problems with invasive plants have now become so widespread, there are businesses that specialize in removing invasive plants for homeowners. Check at your local garden center for recommendations.
I know of no biological controls for this pest. The best way to manage bittersweet is to physically remove the plants, including the root systems, and follow up every year or two by pulling out the new seedlings before they grow too large. To remove established vines, cut the stems near the ground and pull down the tops of the vines, or simply let them dry where they are. Then pull up all the orange-colored roots and leave them to air-dry on the ground. (Bittersweet vines can sprout from any root piece remaining in the ground.)
A more effective alternative to physical removal of the roots is to carefully apply a systemic chemical herbicide to the just-cut stem. This process has minimal impact on the environment and can be done at any time of year, but is easiest while the vines are dormant in winter, late fall, or early spring. Be sure to wear protective clothing and follow all precautions on the label.
– R. Wayne Mezitt, Chairman, Weston Nurseries, Hopkinton, MA