Asiatic or Oriental Bittersweet (Celastrus orbiculatus)

Invader Type: 

Control

Mechanical Control: 

USE EXTREME CAUTION WHEN HAND PULLING! EVEN TINY FRAGMENTS OF THE ROOT CAN REPROUT, QUICKLY MULTIPLYING THE PROBLEM.

 

Hand pull entire plants, including all roots and runners. Place everything into a plastic bag for disposal.

For large plants: Cut climbing or trailing vines close to root collar. Repeat every two weeks.

 

Chemical Control: 

Foliar spray:  This method is best used for dense populations. In the fall, when native plants are losing their leaves, spray a 2% glyphosate or triclopyr solution on the entire leaf surface of the plant.  In order to avoid drift to native plants, spray on calm days.

Cut stump:  Cut plant 4 inches from ground in fall. Treat stumps with a triclopyr herbicide. Glyphosate- based products are not strong enough for this plant.

 

Photos

Photos: 

Description

Identification: 

Oriental bittersweet is a deciduous, woody vine that climbs saplings and trees and can grow over 60 feet in length. 

The leaf shape and fruit color of Asiatic bittersweet (Celastrus orbiculatus) have a very similar appearance to the native Vermont vine, American bittersweet (Celastrus  scandens). The best way to distinguish  between the two plants is by the    location of the flowers and fruits on the stem. On the invasive Asiatic bittersweet, they are scattered along the entire stem (above), while on the native American  bittersweet, they are found at the terminal end of each stem (below).

Reproductive Strategy / Lifecycle: 

Oriental bittersweet primarily reproduces by seed but can also reproduce asexually (runners, roots, root fragments and root crown can all sprout). Plants are dioecious meaning that male and female flowers exist on separate plants. Insects, primarily bees, and wind pollinate the flowers. Flowers bloom May through June and then fruits are produced in July and October. A plant typically produces >350 fruits and each fruit contains between 3-6 seeds. The seeds have a high germination rate (90%) and remain viable for less than one year. Fruits remain on vine well into the winter.

Dispersal: 

Asiatic bittersweet’s seeds are primarily dispersed by birds and mammals. Humans contribute to the plants seed dispersal by using the plant in wreaths. The seeds can also be moved by water.

Habitat: 
Oriental bittersweet is a cold hardy, deciduous vine. It prefers open woods and disturbed areas. It grows best in partial to full sun, and is shade and flood. It is an aggressive vine that can that can grow rapidly, sometimes greater than 10 feet/year, on vertical structures of various diameters.
History: 
Originally introduced as an ornamental
References: 

Photos: Bittersweet Leaves Chris Evans www.invasives.org; Bittersweet Fruits James Allison www.invasives.org.

Threat

Ecological Threat: 

This fast growing vine growth  encircles trees and girdles them, slowly killing the tree. Vines can completely cover other vegetation creating a carpet of vines over a large area.