Celastrus orbiculatus (Oriental Bittersweet)

Celastrus orbiculatus (Oriental Bittersweet) is a fast-growing, deciduous, twining, woody vine with rounded, light green leaves, 2-5 in. long (5-12 cm). The foliage turns butter-yellow in the fall. In late spring to early summer, small greenish-yellow flowers appear in clusters on separate male and female plants. Fertilized female flowers give way to round orange-yellow fruits which split open in fall to expose the scarlet seeds. The berries are quite decorative and attractive, brightening up the fall and winter landscape. Birds feast on them and the fruit is also used for dried arrangements. Female plants need a male pollinator to produce attractive fruit – usually, one male plant is needed for 6-9 female plants.

• Grows up to 30-60 ft. long (9-18 m) and 5-10 ft. wide (1-3 m).
• Thrives in well-drained soil in full sun, but will tolerate partial shade. The best flower and fruit display occurs in full sun.
• No serious insect or disease problems. Deer and rabbit resistant.
• Good for trellises, walls, fences, arbors, and other structures. Strong support is needed for this vigorous species. Can be used as a groundcover too.
• No regular pruning is required. If trimming is necessary, prune this vine in late winter or early spring. This vine blooms on new growth.
• Propagate by seed in containers in an open frame as soon as ripe, or in spring as soon as ripe, or in spring. Root cuttings in winter or semi-ripe cuttings in summer.

Native to Japan, Korea, and China, Oriental Bittersweet spreads both by seeds and root suckers to form large colonies in the wild. It is considered to be an invasive weed in many parts of the United States, Canada, and New Zealand, because of its ability to spread aggressively in the landscape. This fast-growing vine can cover, shade, and outcompete other vegetation. It can even girdle and kill large trees. Birds and other wildlife eat the fruit, thus distributing the seeds. It hybridizes with Celastrus scandens (American Bittersweet), potentially leading to a loss of genetic identity for the US species.
This vine closely resembles American bittersweet, but there are a few differences:

• American Bittersweet produces flowers (and fruits) in single terminal panicles at the tips of the stems; flower panicles and fruit clusters are about as long as the leaves; the leaves are nearly twice as long as wide and are tapered at each end.
• Oriental bittersweet produces flowers in small axillary clusters that are shorter than the leaves and the leaves are very rounded. 

• Find where this species is invasive in the United States.
• Discover beautiful U.S. native plant alternatives.