The Bugwood Network

Nonnative Wisterias
Chinese wisteria, Wisteria sinensis (Sims) DC.
Japanese wisteria, W. floribunda (Willd.) DC.

International Code - WISI, WIFL
FIA survey code - 3251


Miller, James H. 2003. Nonnative invasive plants of southern forests: a field guide for identification and control. Gen. Tech. Rep. SRS–62. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 93 p.

acrobat version

Plant. Deciduous high climbing, twining, or trailing leguminous woody vines (or cultured as shrubs) to 70 feet (20 m) long. Chinese and Japanese wisteria difficult to distinguish due to possible hybridization.

Stem. Woody vines to 10 inches (25 cm) in diameter with infrequent alternate branching. Twigs densely short hairy. Older bark of Chinese wisteria tight and dark gray with light dots (lenticels) compared to white bark of Japanese wisteria.

Leaves. Alternate, odd pinnately compound 4 to 16 inches (10 to 40 cm) long, with 7 to 13 leaflets (Chinese) or 13 to 19 leaflets (Japanese), and stalks with swollen bases. Leaflets oval to elliptic with tapering pointed tips 1.6 to 3 inches (4 to 8 cm) long and 1 to 1.4 inches (2.5 to 3.5 cm) wide. Hairless to short hairy at maturity but densely silky hairy when young. Margins entire and wavy. Sessile or short petioled.

Flowers. March to May. Dangling and showy, stalked clusters (racemes) appearing when leaves emerge, 4 to 20 inches (10 to 50 cm) long and 3 to 3.5 inches (7 to 9 cm) wide. All blooming at about the same time (Chinese) or gradually from base (Japanese). Pealike flowers, corolla lavender to violet (to pink to white). Fragrant.

Fruit and seeds. July to November. Flattened legume pod, irregularly oblong to oblanceolate, 2.5 to 6 inches (6 to 15 cm) long and 0.8 to 1.2 inches (2 to 3 cm) wide. Velvety hairy, greenish brown to golden, splitting on two sides to release one to eight flat round brown seeds, each 0.5 to 1 inch (1.2 to 2.5 cm) in diameter.

Ecology. Form dense infestations where previously planted. Occur on wet to dry sites. Colonize by vines twining and covering shrubs and trees and by runners rooting at nodes when vines covered by leaf litter. Seeds water-dispersed along riparian areas. Large seed size a deterrent to animal dispersal.

Resemble native or naturalized American wisteria, W. frutescens (L.) Poir., which does not form extensive infestations, occurs in wet forests, flowers in June to August after leaves developed, and has 6-inch (15-cm) flower clusters, 9 to 15 leaflets, hairless pods, and slender old vines. Also may resemble trumpet creeper, Campsis radicans (L.) Seem. ex Bureau, which has leaflets with coarsely toothed margins.

History and use. Introduced from Asia in the early 1800s. Traditional southern porch vines.


April
Photo by J. Miller


May
Photo by T. Bodner



September
Photo by T. Bodner

March
Photo by T. Bodner

May
Photo by J. Miller


States with suspected infestations are shown in gray.

Chinese wisteria shown in all images.

Recommended control procedures:

Thoroughly wet all leaves (until runoff) with one of the following herbicides in water with a surfactant:

  • July to October for successive years when regrowth appears—Tordon 101* ‡ as a 3-percent solution (12 ounces per 3-gallon mix), Tordon K* ‡ as a 2-percent solution (8 ounces per 3-gallon mix), or Garlon 4 as a 4-percent solution (15 ounces per 3-gallon mix)
  • July to September for successive years when regrowth appears—Transline* † as a 0.5-percent solution in water (2 ounces per 3-gallon mix) when safety to surrounding vegetation is desired
  • September to October with repeated applications—a glyphosate herbicide as a 2-percent solution (8 ounces per 3-gallon mix)

*   Nontarget plants may be killed or injured by root uptake.
†   Transline controls a narrow spectrum of plant species.
‡   When using Tordon herbicides, rainfall must occur within 6 days after application for needed soil activation. Tordon herbicides are Restricted Use Pesticides.


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USDA Forest ServiceUSDA APHIS PPQThe Bugwood Network University of Georgia Bargeron, C.T., D.J. Moorhead, G.K. Douce, R.C. Reardon & A.E. Miller
(Tech. Coordinators). 2003. Invasive Plants of the Eastern U.S.:
Identification and Control. USDA Forest Service - Forest Health
Technology Enterprise Team. Morgantown, WV USA. FHTET-2003-08.