Bill Johnson

Oriental Bittersweet

Celastrus orbiculatus Thunb.
Staff-tree family (Celastraceae)

Origin: Eastern Asia, Korea, China and Japan

Oriental bittersweet was introduced into the United States in the 1860s as an ornamental plant and it is still widely sold for landscaping despite its invasive qualities. It is often associated with old home sites, from which it has escaped into surrounding natural areas.

Distribution and Habitat
Oriental bittersweet has been reported to be invasive from Maine to North Carolina west to Wisconsin and Missouri. It occurs in forest edges, open woodlands, fields, hedgerows, coastal areas, salt marshes and disturbed lands. While often found in more open, sunny sites, its tolerance of shade allows it to invade forested areas.

Ecological Threat
Oriental bittersweet is a vigorous growing plant that threatens native vegetation from the ground to the canopy level. Thick masses of vines sprawl over shrubs, small trees and other plants, producing dense shade that weakens and kills them. Shrubs and trees can be killed by girdling and by uprooting as a result of excessive weight of the vines. In the Northeast, Oriental bittersweet appears to be displacing the native American bittersweet (Celastrus scandens) through competition and hybridization.

Description and Biology

Chris Evans, River to River CWMA

Prevention and Control
Do not buy, plant, transplant Oriental bittersweet or dispose of live or dead seed-containing material. Manual, mechanical and chemical methods can be employed to control it. Vines can be pulled out by the roots, cut repeatedly or treated with systemic herbicides (see Control Options). No biological controls are currently available for this plant.

Native Alternatives
Caution: Although our native bittersweet (Celastrus scandens) would be an excellent alternative plant to use as an alternative, many nurseries often confuse it with the exotic invasive bittersweet under the native label. Be certain of the species you are buying or choose another plant. Also, because of hybridization between the native and exotic species, many feel it is irresponsible to plant the native species when the invasive occurs in the area.


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Last updated:11-Nov-2010