Oriental bittersweet (Celastrus orbiculatus) is an aggressive woody vine introduced from East Asia in the 1860s that threatens native trees, shrubs, and infrastructure throughout the United States. The vine rapidly chokes out native vegetation by smothering it with dense foliage and physically constricting stems and trunks. It can reach up to 100 feet in length and several inches in diameter, causing mature trees to be vulnerable to wind and ice damage due to added weight and structural stress. Eradication of this invasive species requires a multi-pronged approach combining mechanical removal with targeted chemical treatments to achieve permanent control.
Identifying the Target Plant
Accurate identification is the first step, as the invasive Oriental bittersweet can be confused with the native American bittersweet (Celastrus scandens). The most reliable distinction is the arrangement of flowers and fruit on the female vines. Oriental bittersweet produces its clusters of berries along the stem at the leaf axils, while the native species produces fruit in long, terminal clusters only at the tips of the branches. The leaves of the invasive species are typically round or broadly oval, and the yellow-orange fruit capsule reveals a fleshy, scarlet-red interior that persists through winter. Furthermore, the root system displays a distinct, bright orange color, which is a helpful identifier when removing young plants.
Physical Removal Methods
For small, isolated plants or young seedlings, hand-pulling is an effective method, provided the entire root system is removed. Seedlings are easiest to pull when the soil is moist, and pulling should be done slowly and steadily to minimize breakage. If the root breaks, the remaining portion will likely resprout vigorously.
For larger, mature vines climbing up trees, the immediate priority is to relieve the host tree from the vine’s damaging constriction. This is accomplished by making two cuts on the vine: one cut at a comfortable height, such as chest-high, and a second cut near the ground. The upper section of the vine should be pulled away from the tree trunk, though it is usually safest to leave the dangling vine in the canopy to decay naturally over time.
Cutting the vine without treating the remaining stump will result only in temporary relief, as the root crown will quickly send up multiple new shoots. Repeated cutting over several growing seasons is required to exhaust the root system if chemical control is not an option. In areas where digging is feasible, the entire orange root mass must be excavated to prevent regrowth.
Strategic Herbicide Application
The most effective method for eradicating established, woody bittersweet involves the use of systemic herbicides. This approach ensures the poison translocates down into the deep root system, which is necessary for complete rootkill. The cut-stump method is the preferred technique, particularly for large vines or in areas where desirable plants are nearby.
To perform the cut-stump treatment, the vine is cut close to the ground, leaving a short stub. A concentrated herbicide solution (typically containing 20-25% glyphosate or 20% triclopyr) is then applied immediately to the freshly cut surface. It is important to treat the cambium layer—the narrow ring just inside the bark—within minutes of cutting, as this tissue transports the herbicide to the roots. Applications are most effective in late summer and fall, after July 1st and before the first hard frost, when the vine is actively transporting nutrients to its roots.
A second effective chemical strategy is the basal bark treatment, used for vines that are difficult to cut. This method involves applying an oil-based solution of triclopyr ester, usually at a 20% concentration, directly to the intact bark. The solution is painted in a continuous band around the lower 12 to 18 inches of the vine, allowing the oil to penetrate the bark. This technique should be applied to dry vines and care must be taken to avoid contact with the bark of any host tree.
Long-Term Monitoring and Disposal
Eradicating Oriental bittersweet requires persistent monitoring because its seeds can remain viable in the soil for years, and its root system is prone to resprouting. After initial treatment, the area should be checked frequently, especially throughout the following growing season, for any new shoots or seedlings. New growth from cut stumps should be either recut and retreated with herbicide or treated with a foliar spray once enough leaf surface is present for absorption.
Proper disposal of the plant material is necessary to prevent further spread. Cut vines, particularly those bearing the distinctive red and yellow berries, should not be composted, as the seeds can remain viable. The safest method for disposal is to bag the material in heavy-duty plastic bags and send it to a landfill or arrange for incineration where permitted. Complete control generally requires a commitment of three to five years of consistent effort and follow-up treatments.