Chinese wisteria (Wisteria sinensis)

Synonyms: Glycine sinensis, Wisteria chinensis, Rehsonia sinensis

Common Names: Purple wisteria, Chinese-glycine

Description:

Chinese wisteria (Wisteria sinensis) is a fast-growing woody vine from China, long planted for its showy, fragrant clusters of lavender flowers [2][3]. It climbs by twining tightly around trees and structures and has escaped from gardens into the wild across much of the eastern United States [1][2]. MISIN tracks it because it strangles and shades out native trees and forms dense thickets that smother other plants [1].

Habit:

Chinese wisteria is a large, woody climbing vine that twines around trees, fences, and anything else it can reach, with old stems growing as thick as a person's leg [1][2]. A useful clue is the direction it twists: Chinese wisteria winds counterclockwise around its support [1][2]. Its leaves are divided into many small leaflets (usually 7 to 13) arranged along a central stalk [2]. The standout feature is the flowers ? long, drooping clusters of blue-violet, pea-shaped, fragrant blooms, 6 to 12 inches long, that open nearly all at once in spring [2].

It is easiest to spot in spring, around April and May, when the showy lavender flower clusters bloom ? often before or just as the leaves come out [2]. Later in the year, look for the twining woody stems and the velvety, bean-like seed pods, which hang in drooping clusters and persist into fall and winter [2].

At-a-glance cues:

1. Woody vine that twines counterclockwise around trees and supports, with thick old stems [1][2]
2. Leaves divided into 7 to 13 small leaflets along a central stalk [2]
3. Long, drooping clusters of fragrant, blue-violet, pea-shaped flowers (6 to 12 inches) that open all at once in spring [2]
4. Velvety, brown, bean-like seed pods hanging in clusters into fall and winter [2]

Leaves:

1. Arrangement: alternate, and divided into many leaflets along a central stalk (pinnately compound) [2]
2. Leaflet number: usually 7 to 13 leaflets per leaf [2]
3. Shape: leaflets elliptic to oval with smooth (untoothed) edges and a pointed tip [2]
4. Surface: finely hairy, especially when young [2]

Stems:

1. Habit: a woody, deciduous, twining vine that climbs high into trees and over structures [1][2]
2. Twining direction: winds counterclockwise around its support ? a key trait separating it from Japanese wisteria [1][2]
3. Size: stout gray-brown stems that thicken with age, reaching well over a foot across on old plants [2]

Flowers:

1. Color: blue-violet to lavender (some garden forms white or pink) [2]
2. Shape: small, fragrant, pea-shaped flowers [2]
3. Arrangement: in long, drooping clusters (racemes) 6 to 12 inches long, opening nearly all at once [2]
4. Bloom time: spring, often before or as the leaves emerge [2]

Fruit and seeds:

1. Fruit type: a flattened, bean-like pod 4 to 6 inches long, hanging in drooping clusters [2]
2. Surface: velvety-hairy; brown when ripe [2]
3. Seeds: a few flat, round, brown seeds per pod; the pod splits open to release them [2]
4. Persistence: the pods often hang on the vine into fall and winter [2]

Habitat:

Chinese wisteria is native to China [2][3]. It was brought to North America as a flowering garden vine and has escaped into the wild across much of the eastern United States [2][4].

It grows in sunny to partly shaded places and is most common along forest edges, roadsides, fence rows, ditches, rights-of-way, and old home sites, from which it climbs into nearby trees and spreads into the woods [1][2]. It tolerates a range of soils and, once established, is hard to remove [1].

Reproduction:

Chinese wisteria spreads two ways. Close to the parent plant, stems that run along the ground take root where they touch the soil, so a vine can creep outward and form a dense patch [1]. It also makes seeds: the velvety pods release flat seeds that can be carried long distances by water, which is why it often turns up along streams and ditches [1].

It is a long-lived woody vine that leafs out and flowers in spring and ripens its pods by fall [2]. When a climbing vine is cut, it sprouts back vigorously from the cut stem, so removal usually takes repeated effort over time [1]. For control, the key is to catch and remove vines early, before they climb high into trees and spread [1].

Impact and Damage:

For homeowners, Chinese wisteria is a beautiful vine that quickly becomes a problem. It climbs and twines so tightly that it can strangle and kill trees and shrubs, pull down fences and structures with its weight, and resprout stubbornly after it is cut [1]. Once it is established on a property, it is difficult to get rid of [1].

For natural area stewards, the concern is the harm to woodlands. Chinese wisteria can shade out native trees or strangle them with its thick, heavy growth, and when those trees die, the open canopy lets in full sun that helps the vine grow even faster [1]. It also forms dense thickets that smother and suppress native plants on the ground [1]. Because it spreads from plantings and along waterways, finding and removing escaped vines early is the most effective way to limit the damage [1].

Similar species:

Chinese wisteria is confused with other wisterias and climbing vines. The clearest clues are the direction it twines (counterclockwise) and its long clusters of lavender flowers that open all at once [1][2].

Japanese wisteria (Wisteria floribunda) is the closest match and is also invasive. The surest difference is the twining direction ? Japanese wisteria winds clockwise, the opposite of Chinese wisteria. It also tends to have more leaflets per leaf and longer flower clusters that open gradually from the base rather than all at once [1][2].

American wisteria (Wisteria frutescens) is a native vine that is a good substitute for the invasive ones. It blooms later, after the leaves are out, in shorter, more compact flower clusters, and its seed pods are smooth and hairless rather than velvety [2].

Trumpet creeper (Campsis radicans) is a native climbing vine that grows in the same kinds of places. It is easy to separate by its showy orange-red trumpet-shaped flowers, which are nothing like the dangling lavender pea flowers of wisteria [2].

Monitoring and rapid response:

Signs to watch for:

1. Woody vines twining counterclockwise up trees, fences, and old plantings along forest edges, roadsides, and ditches [1][2]
2. Long, drooping clusters of fragrant lavender flowers in spring, opening all at once [2]
3. Velvety brown bean-like pods hanging in clusters into fall and winter [2]

What you can do:

1. Pull or dig out seedlings and young vines, including the roots, while the soil is moist [1]
2. Cut climbing vines near the base to free a tree, but expect the cut stems to resprout, so cut again as new growth appears ? repeated cutting over time is needed [1]
3. Cut and bag the seed pods before they ripen so the seeds cannot spread, and remove any ground-running stems that have rooted [1]
4. Do not plant Chinese or Japanese wisteria ? choose native American wisteria or other native vines instead [1][2]
5. For natural areas, volunteer crews should catch new vines early, before they climb high into the canopy, and work over several seasons to cut and dig out established plants, prioritizing vines that are strangling trees and small outliers near high-quality woods [1]

When to call a professional:

1. Large, established vines high in the tree canopy that resprout strongly after cutting [1]
2. Dense, long-standing infestations across a woodlot or along a waterway that need a coordinated, multi-year plan [1]
3. For chemical control options, contact a licensed applicator or your local cooperative extension office.

Report sightings to MISIN. Help track this species' spread by submitting observations through the MISIN web site or the MISIN mobile app (Android, iOS, Windows, and macOS). Photos at multiple angles paired with a precise GPS location are the most valuable data for confirming new occurrences and triggering rapid-response review.

Credits:

1. University of Maryland Extension. "Invasives in Your Woodland: Chinese and Japanese Wisteria." extension.umd.edu
2. NC State Extension Gardener Plant Toolbox. Wisteria sinensis (Chinese Wisteria). plants.ces.ncsu.edu
3. Plants of the World Online (POWO), Royal Botanic Gardens, Kew. Wisteria sinensis (Sims) DC. powo.science.kew.org
4. USDA NRCS Plants Database. Wisteria sinensis (Sims) Sweet. plants.usda.gov

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