Chinese Wisteria

What is Chinese wisteria?

Chinese wisteria identification hinges on leaflet count and bloom timing: compound leaves with 7 to 13 leaflets, and long hanging flower clusters that open nearly all at once on bare stems in early spring. Native to China and planted for generations around American homes, it is now widespread across the eastern United States and has escaped into woods, fence rows and roadsides. It hybridizes freely with Japanese wisteria, so many escaped plants are a mix of the two, and both are managed the same way.

The trouble is its size and grip. Old vines grow thick and trunk-like, wrap tightly around trees and shrubs, and slowly strangle and shade them until they die. On the ground it forms dense tangles that replace other plants and block people and animals. Once established it is difficult to eradicate and can persist for many years. The record Chinese wisteria, in Sierra Madre, California, had a stem length of more than 450 feet, which gives a sense of how far a single plant can reach.

Chinese Wisteria identification: what to look for

Spring flowers make it easy to spot, but you will often need to identify it in summer or winter. Count the leaflets, watch how the flowers in a cluster open, and check the pods and bark. Chinese and Japanese wisteria can be hard to separate when they are not flowering or in pod, and hybrids blur the differences further.

• Leaves: Alternate and compound, about a foot long overall, with 7 to 13 leaflets, most often 11. Leaflets are oval to elliptic, 1 to 4 inches long, smooth-edged, silky-hairy when young and hairy along the midrib underneath.
• Stems and bark: A twining woody vine that can reach about 70 feet. Old stems become massive and trunk-like. Older bark is tight and dark gray with pale pores, while Japanese wisteria bark tends to be whitish. Sources disagree on which direction each species twines, so do not rely on twining direction alone.
• Flowers: Fragrant, pea-like flowers, usually lavender to violet but sometimes pink or white, in hanging clusters from about 6 inches to more than a foot and a half long. They bloom from March to May before the leaves emerge, and the flowers in a cluster open nearly all at once.
• Pods and seeds: Flattened, velvety, densely hairy pods 2.5 to 6 inches long hang in clusters from July into fall. Each holds one to several flat, brown seeds.
• Runners: Besides climbing, stems trail along the ground and root along their length where they are covered by leaf litter, which is how a single planting turns into a thicket.

Where it grows in the United States

Chinese and Japanese wisteria are widespread across the eastern United States, and a USDA Forest Service field guide reports scattered dense infestations in every southern state, with especially heavy ones in South Carolina and southwestern Alabama. NC State Extension lists Chinese wisteria as hardy in USDA zones 5 through 8, and the record-size vine grows in Sierra Madre, California. USDA PLANTS lists it as introduced in the lower 48 states and Hawaii. Infestations usually trace back to an old planting, and Mississippi State Extension notes it is common around old houses.

It grows best and flowers most heavily in full sun, but it tolerates shade while it climbs toward light. It prefers moist, well-drained soil yet adapts to many soil types and to wet or dry sites. Look for it at forest edges, along roadsides and ditches, on fence rows, and in woods around old house sites. Along streams, its large seeds can be carried by water, so infestations sometimes follow creek corridors. Wildlife rarely moves the seed because the seeds are big and the fruit is poisonous.

Chinese Wisteria look-alikes

A few plants get mixed up with it:

• Japanese wisteria (Wisteria floribunda): Has more leaflets, 13 to 19 per leaf, and its flowers open gradually from the base of the cluster toward the tip instead of all at once. Older bark tends to be whitish. It is just as invasive and hybridizes with Chinese wisteria.
• American wisteria (Wisteria frutescens): The native wisteria of the Southeast. It blooms later, June to August after the leaves are out, in shorter clusters about 6 inches long, has 9 to 15 leaflets, thin, smooth, papery pods without velvet, and slender old vines. It is far less aggressive and tends to grow in and around wetlands.
• Trumpet creeper (Campsis radicans): Another woody vine with compound leaves, but its leaflets have coarse teeth and white hairs on the veins underneath, while wisteria leaflets are smooth-edged.

How to get rid of Chinese wisteria

Pulling, digging and mowing: Mechanical control is slow and labor-intensive, but it is the place to start. Snap off young shoots and pull seedlings when the soil is moist, getting as much root as you can, since root pieces left behind can sprout again. Follow runners along the ground and pull or cut them where they have rooted under leaf litter. Older vines have to be cut; cut vines climbing into trees near the ground to stop the girdling, then treat the stump or keep cutting the sprouts, because cut vines resprout. Bag pods and cut material and send them to the trash, and do your pulling and cutting when pods are absent so you do not spread seed. Burning can clear debris and sever climbing vines, but repeated burning will not control it.

Cultural control matters most, because the right conditions keep it from coming back.

• Do not plant Asian wisteria. For a flowering vine, NC State and Maryland Extension suggest natives such as American wisteria, crossvine, trumpet honeysuckle or virgin's-bower clematis.
• Pick and bag seed pods before they split, especially near streams and ditches where seeds travel in water.
• Walk the area around old plantings and look under leaf litter for rooted runners, which keep the thicket growing.
• Plan for several years of follow-up; established wisteria persists and resprouts for years.

Herbicides: Mississippi State Extension notes that few labeled recommendations exist for wisteria, but several methods are used. For cut stumps, sever the main stem and immediately apply glyphosate or triclopyr just inside the bark of the stump. The frill or hack-and-squirt method cuts openings into the bark every couple of inches around the stem and puts herbicide into them. Basal bark treatment with an oil-based triclopyr product on the lower 18 to 24 inches of the trunk works best on stems under about 4 inches across and just before bud break in spring. For low regrowth, foliar sprays of triclopyr in midsummer or glyphosate in early fall work, with repeat treatments in following years. Clopyralid is narrow-spectrum and can be used where wisteria is draped over desirable trees, while picloram is taken up through tree roots and can injure or kill nearby trees, so keep it well away from trees you want to save. Large vines can be stem-injected any time except March and April. Use only products labeled for your site, read the full label, and remember the label is the law. If you hire someone to spray, make sure they hold your state’s pesticide applicator license; the rules for each state are in our pesticide applicator license guide.

Keeping it from coming back

Intentional planting is the main reason wisteria has spread, so the best prevention is not planting it and replacing existing Asian wisteria with a native vine. Maryland now requires an invasive-plant sign on Chinese wisteria sold in the state, so check your own state's rules before you buy.

If you live near an old planting, watch your property line and any creek or ditch below it for runners and seedlings, and pull them while they are small. Remove pods before they ripen to keep seed out of waterways.

Questions we get about Chinese wisteria

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