Asiatic Bittersweet

Fact SheetTreatmentCelastrus orbiculatus

Invader Images

    • Asiatic bittersweet leaves and fruit
      Asiatic bittersweet leaves
    • Asiatic bittersweet infestation
      Asiatic bittersweet infestation
    • Asiatic bittersweet fruits
      Asiatic bittersweet fruits

Common Look-alikes

    • American bittersweet with terminal fruits
      American bittersweet with terminal fruits

Identification

Appearance

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

Foliage

The alternate, elliptical to circular leaves are light green in color and 2-5 in. (5-13 cm) long.

Flowers

Small, inconspicuous, axillary, greenish-white flowers bloom from May to early June. Oriental bittersweet closely resembles American bittersweet (Celastrus scandens). The main difference: Celastrus scandens has flowers and fruits at the terminal ends of branches; Celastrus orbiculatus has flowers scattered along the entire stem.

Fruit

The small globose fruits are green when young; ripen to yellow; then split to reveal showy, scarlet berries that persist into winter.

Check out the downloadable fact sheet above.

 

 

Biology

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. Birds and other wildlife eat the fruit, thus distributing the seeds. It hybridizes with American bittersweet (Celastrus scandens) potentially leading to loss of genetic identity for the native species.

Origin

Originally introduced as an ornamental in 1860s

Habitat

Fields, forests, forest edges, disturbed sites, ornamental plantings, shade tolerant

Life Cycle

Asiatic 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 more than 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.

Management Options

This species is quarantined: Class B Noxious Weed

Check out the downloadable treatment sheet above.

Mechanical Management

  • Use extreme caution when hand pulling. Even tiny fragment of the root can resprout, 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 Management

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.

  • Be careful not to damage or kill nearby native plants when conducting management work, and when using herbicides, always follow the instructions on the label.

Vermont Distribution

How You Can Help

Citations

Photo Credit

Asiatic bittersweet, E Spinney, VT FPR

Asiatic bittersweet infestation, 1509001, Max Williamson, USDA Forest Service

Asiatic bittersweet fruit, 2308050, Leslie J. Mehrhoff, University of Connecticut

American bittersweet fruit, 5477233, Leslie J. Mehrhoff, University of Connecticut

Information Credit

Center for Invasive Species and Forest Health, Oriental Bittersweet

The Nature Conservancy

Video: Purdue University Extension, Invasive Plant Species: Oriental Bittersweet