Oriental bittersweet

About

A woody, twining vine from East Asia, often used in fall wreaths for its orange-and-red berries, that climbs high over trees and shrubs. Birds spread the seeds widely, and cut vines resprout hard from the roots.

Also called Asian bittersweet, Asiatic bittersweet, round-leaved bittersweet, round leaf bittersweet, climbing spindleberry

How to identify it

Look for

Leaves are alternate, 2 to 5 inches long with finely toothed edges; lower leaves are nearly round and upper ones more football-shaped, and they turn bright yellow early in fall. Female plants carry small clusters of yellow-orange capsules at nearly every leaf joint along the stem; in fall the capsules split to show bright red seeds.

Look-alikes

Native American bittersweet, Celastrus scandens, has flowers and fruit only in clusters at the tips of the stems, not at each leaf joint, and more football-shaped leaves. The two can cross, so if you're unsure, have it checked before you remove it.

Where it grows

Forest edges, hedgerows, fence lines, roadsides and yard edges, especially moist, disturbed ground.

When

Flowers in May and June; fruit ripens from about July to October and hangs on through winter.

How it spreads

Birds eat the fruit and drop the seeds, and a typical plant bears hundreds of fruits a year; it also sprouts from roots, root pieces and the root crown, especially after cutting.

Most common in

Where it is regulated

Minnesota lists it as a prohibited noxious weed.

What to do, gentlest first

Start at the top. Weed killers are a last step; always read and follow the label.

1. Don't use the berries in wreaths Prevent

   The seeds stay alive even after the branches dry, so decorations can start new infestations. Pull seedlings as soon as you spot them.

2. Pull young vines and cut big ones at the base By hand

   Pull small plants, roots and all. Cut large vines at ground level to save the trees they climb, then keep cutting the resprouts to wear down the roots.

   Remove fruit before discarding vines; don't compost berries or roots.

3. Cut-stump, basal bark or foliar triclopyr or glyphosate Conventional spray

   Paint oil-based triclopyr on fresh cuts, spray triclopyr in oil on the lower bark of stems under 6 inches thick, or spray regrowth with triclopyr or glyphosate from July on, at least 8 weeks after cutting.

   Read and follow the label. Many lawn and brush killers also harm garden plants, so keep spray and drift off anything you want to keep. Avoid treating big tangles of vines in the root zone of trees you want to keep, since the herbicide can injure them.

Uses, wildlife and pets

For wildlife

Many birds, like robins, thrushes, mockingbirds and starlings, eat the fruit, which is how it spreads.

Pets

Oriental bittersweet itself isn't listed by the ASPCA, but its close relative American bittersweet (Celastrus scandens) is listed as toxic to dogs, cats and horses.