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FACT SHEET: JAPANESE WISTERIA

Japanese Wisteria 

Wisteria floribunda (Sims) DC. 

Pea family (Fabaceae) 

NATIVE RANGE 

Japan 

DESCRIPTION 

Japanese wisteria is a deciduous, woody ornamental vine that climbs trees high 

into the canopy, to more than 60 feet. It twines upwards in a counter-clockwise

direction. The stems are slender, brown and densely pubescent when young, 

becoming hairless with age. Older plants can grow to 15 in. or more in diameter. 

The leaves are alternate and compound, 8-12 in. long, with 7-17 (19) leaflets 

which are egg-shaped and have slightly wavy margins. In the mid-Atlantic region 

flowering occurs in April before the leaves expand. Flowers are violet to violet 

blue, occur in pendulous racemes (clusters) 1-3 ft in length and open sequentially 

from the base to the tip. The flowers are 0.6-0.7 in. long on stalks (pedicels) 0.6-

0.8 in. long. Fruits are velvety pods 4.5-7.5 in. long, broader towards the tip, and 

contain 3-6 glossy orbicular violet purple seeds each about 0.5 in. across. The 

pods begin to appear soon after flowering, mature during the summer and may 

persist for quite a while on the vines. 

Look-alikes: 1) American wisteria (Wisteria frutescens), native to the 

southeastern U.S. into southern Virginia, twines clockwise, stems brown to 

reddish brown and hairless, leaves with 9-15 leaflets, lower surface somewhat milky green, flowers in May after the leaves 

have expanded, flower clusters are 1.5-6 in. long, shorter than both Chinese and Japanese wisteria, flower pedicels 0.2-

0.4 in long, seedpods 2-4 in. long, brown and smooth (non-hairy); 2) Chinese wisteria (Wisteria sinensis) also twines 

clockwise; stems are stout, gray-brown and covered with fine white hairs; leaves have 9 to 11 (7-13) leaflets; flowers are 

lavender to purple in racemes 6-8 in. long and open mostly all at once; flowers are 0.8-0.9 in. long on stalks (pedicels) 

0.6-0.8 in. long; 3) trumpet creeper (Campsis radicans) native to central and eastern U.S.; has opposite leaves with 

toothed leaflets and orange-red flowers that bloom from late spring through summer and into fall.. 

ECOLOGICAL THREAT 

The hard woody vines of Japanese wisteria twine tightly around host tree trunks and branches and cut through the host 

tree bark, eventually girdling and killing it. On the ground, new vines germinating from seed or sprouting from rootstocks 

form dense thickets that smother and shade out native vegetation and impede natural plant community development. As 

girdled trees die, canopy gaps are created which increase the amount of sunlight reaching the forest floor. While this may 

temporarily favor some native species, it also stimulates vigorous growth and spread of wisteria. 

DISTRIBUTION IN THE UNITED STATES 

Japanese wisteria has been reported to be invasive in the mid-Atlantic and Southeast from Tennessee to South Carolina 

north to New Jersey and by six national parks in that area. Its distribution may span a much larger area as it is often 

misidentified as Chinese wisteria which is reported to occur from Louisiana to Massachusetts. Identification of these two 

very similar looking exotic species is difficult and frequently confused. 

HABITAT IN THE UNITED STATES 

Wisteria prefers full sun, but established vines will persist and reproduce in partial shade. Vines climb trees, shrubs and 

manmade structures. It is tolerant of a variety of soil and moisture regimes but prefers deep, loamy, well drained soils. 

Infestations are commonly found along forest edges, roadsides, ditches, and rights-of-way. 
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BACKGROUND 

Japanese wisteria was introduced from Japan around 1830 as an ornamental. It has been grown extensively in the 

southern U.S. as a decorative addition to porches, gazebos, walls, and gardens. Most infestations in natural areas are a 

result of escapes from landscape plantings. 

BIOLOGY & SPREAD 

Wisteria is a long-lived perennial, surviving 50 years or more. Vegetative 

reproduction is the primary means of growth and spread. Slender stems (stolons, 

runners) grow horizontally across the ground and develop new plants (roots and 

shoots) at the nodes. Seeds may be produced when conditions are favorable. In 

riparian areas these may be carried by water downstream for great distances. 

MANAGEMENT OPTIONS 

Manual, mechanical and chemical control methods are all effective in removing 

and killing wisteria. Employing a combination of methods often yields the best 

results and may reduce potential impacts to native plants, animals and people. 

The method you select depends on the extent and type of infestation, the amount 

of native vegetation on the site, and the time, labor and other resources available 

to you. Whenever possible and especially for vines climbing up trees or buildings, 

a combination of cutting followed by application of concentrated systemic 

herbicide to the cut surfaces of the rooted living portions will provide better kill of 

the targeted plants. For large infestations spanning extensive areas, a foliar 

herbicide may be a better choice rather than manual or mechanical means which 

could result in extensive disturbance to the soil. 

Biological

There are no biological control agents currently available for this plant. 

Chemical 

Systemic herbicides like triclopyr (e.g., Garlon® 3A and Garlon® 4) and glyphosate (e.g., Accord®, Glypro®, Rodeo®) are 

absorbed into plant tissues and carried to the roots, killing the entire plant within about a week. Glyphosate is a nonselective systemic herbicide that may kill non-target plants that are only partially contacted by spray. Triclopyr is selective

to broadleaved species and is a better choice if native grasses are present. Ambient air temperature should be above 

65oF for all foliar treatments. Glyphosate products referred to in this fact sheet are sold under a variety of brand names 

(Accord®, Rodeo®, Roundup Pro® Concentrate) and in three concentrations (41.0, 50.2 and 53.8% active ingredient). 

Other glyphosate products sold at home improvement stores may be too dilute to obtain effective control. Triclopyr comes 

in two forms – triclopyr amine (e.g., Garlon® 3A, Brush-B-Gone®, Brush Killer®) and triclopyr ester (e.g., Garlon® 4, 

Pathfinder®, and Vinex®). Because Garlon® 3A is a water-soluble salt that can cause severe eye damage, it is 

imperative that you wear protective goggles to protect yourself from splashes. Garlon® 4 is soluble in oil or water, is highly 

volatile and can be extremely toxic to fish and aquatic invertebrates. It should not be used in or near water sources or 

wetlands and should only be applied under cool, calm conditions. 

Herbicide applications can be made almost any time of year as long as temperatures are above 55-60 degrees Fahrenheit 

for several days and rain is not expected for at least 24 hours. Fall and winter applications will avoid or minimize impacts 

to native plants and animals. Repeated treatments may be needed for control of large or long-established infestations. In 

areas where spring wildflowers or other native plants occur, application of herbicides should be conducted prior to their 

emergence, delayed until late summer or autumn, after the last killing frost occurs, or carefully targeted. Herbicidal contact 

with desirable plants should always be avoided. If native grasses are intermingled with the wisteria, triclopyr should be 

used because it is selective for broad-leaved plants and will not harm grasses. Follow-up monitoring should be conducted 

to ensure control of any regrowth. 

Basal bark application 

Use a string trimmer or hand saw to remove some of the vine foliage in a band a few feet wide and a few feet above the 

ground at comfortable height. To the exposed vine stems, apply a 20% solution of triclopyr ester (Garlon® 4) (2.5 quarts 

per 3-gallon mix) in commercially available basal oil with a penetrant (check with herbicide distributor). As much as 

possible, avoid application of herbicide to the bark of the host tree. This method can be employed essentially year-round 

when daily temperatures remain around 50°F for several days. Efficacy will vary seasonally. 
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Cut stump application 

Use this method in areas where vines are established within or around non-target plants or where vines have grown into 

the canopy. Cut each vine stem close to the ground (about 2 in. above ground) and immediately apply a 25% solution of 

glyphosate (e.g., Accord®) or triclopyr (e.g., Garlon® 3A) mixed with water to the cut surface of the stem. Glyphosate 

applications are effective at temperatures as low as 40°F. Triclopyr applications are effective at temperatures below 60°F 

as long as the ground is not frozen. Subsequent foliar applications may be necessary to control new seedlings or sprouts. 

Homeowners can apply products like Brush-B-Gone®, Brush Killer® and Roundup Pro® concentrate undiluted to cut 

stems. Use a paint brush or a plastic spray bottle to apply the herbicide to cut surfaces. 

Foliar application 

Foliar spray herbicide applications are used to control large infestations of exotic wisterias. It may be necessary to 

precede foliar applications with cut stem treatments to reduce the risk of damaging non-target species. To the leaves, 

apply a 2% solution (8 oz per 3 gal. mix) triclopyr ester (Garlon® 4) or triclopyr amine (Garlon® 3A) mixed in water with a 

non-ionic surfactant. In Rhode Island, concentrations as low as 1% in mid-summer and 0.05% in September have been 

very effective. Thoroughly wet the foliage but not to the point of runoff. The ideal time to spray is after much of the native 

vegetation has become dormant (October-November) to avoid affecting non-target species. A 0.5% concentration of a 

non-ionic surfactant is recommended in order to penetrate leaf cuticle. If the 2% rate is not effective try an increased rate 

of 3 or up to 5%. Ambient air temperature should be above 65°F. For dense, low patches, another alternative is to cut the 

entire patch to the ground early in the growing season using a mower, weed-whip, machete or other tool. About one 

month later, apply 1-2% solution of triclopyr ester (Garlon® 4) or triclopyr salt (Garlon® 3A) in water to the cut patch using 

a backpack sprayer. This method has achieved complete kill of the targeted vines with little off-target damage or root 

uptake by adjacent plants. A third herbicide, clopyralid (e.g. Transline®) is also available and is selective to plants in three 

families: aster (Asteraceae), buckwheat (Polygonaceae), and pea (Fabaceae), of which wisteria is a member. This 

herbicide is effective at a concentration of 0.5%. Clopyralid has the potential to leach into groundwater and not may be 

appropriate for many sites depending on conditions. Consider this potential environmental problem when deciding what 

product to use. When using clopyralid, take precautions to reduce or prevent leaching. 

Manual and Mechanical 

Always wear gloves and long sleeves to protect your skin from poison ivy and barbed or spined plants that often grow 

amongst the invasive vines. For small infestations, plants can be hand-pulled along with the root portions. If fruits are 

present, the vines should be bagged in plastic trash bags and disposed of in a landfill or, alternatively, piled up and 

allowed to dessicate onsite. Dried piles of pulled material can either be left on-site and monitored the next year for new 

growth or hauled away. For climbing vines, first cut the vines near the ground at a comfortable height to kill upper portions 

and relieve host tree. Vines can be cut using pruning snips or a pruning saw for smaller stems and a hand axe or chain 

saw for larger stems. Try to minimize damage to the host tree’s bark. Rooted portions will remain alive and should be 

pulled, repeatedly cut to the ground or treated with herbicide. Cutting without herbicide will require vigilance and repeated 

cutting because new plants will resprout from the stem base. 

Grubbing, removal of entire plants from the roots up, is appropriate for small initial populations or environmentally 

sensitive areas where herbicides cannot be used. Using a pulaski, weed wrench or similar digging tool, remove the entire 

plant, including all roots and runners. Juvenile plants can be hand pulled depending on soil conditions and root 

development. Any portions of the root system not removed may resprout. Mature fruits should be bagged and disposed of 

in a trash dumpster to prevent spread by seed. Cut climbing or trailing vines low, close to the root collar if possible. This 

technique, while labor intensive, is feasible for small populations, as a pretreatment for large impenetrable infestations, or 

for areas where the use of herbicide is not desirable or possible. Wisteria will continue to resprout after each cutting until 

its root stores are exhausted. For this reason, cutting should begin early in the growing season and, if possible, sprouts 

should be cut every few weeks until autumn. Cutting will slow down growth, exhaust some of the plants resources and 

help prevent flowering and seed production. 

USE PESTICIDES WISELY: Always read the entire pesticide label carefully, follow all mixing and application instructions and wear all 

recommended personal protective gear and clothing. Contact your state department of agriculture for any additional pesticide use 

requirements, restrictions or recommendations. 

NOTICE: mention of pesticide products on this page does not constitute endorsement of any material.
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CONTACT 

For more information on the management of Japanese wisteria, please contact: 

• Frank Archuleta, National Park Service, National Capital Region, Exotic Plant Management Team, 

frank_archuleta(at)nps.gov 

• Kris Johnson, Great Smoky Mountains National Park, Gatlinburg, TN, kris_johnson(at)nps.gov 

• Jil Swearingen, National Park Service, National Capital Region, Washington, DC, jil_swearingen(at)nps.gov 

• Sylvan Kaufman, Adkins Arboretum, Ridgely, MD, skaufman(at)adkinsarboretum.org 

SUGGESTED ALTERNATIVE PLANTS 

Some examples of alternative plants to consider include American wisteria (Wisteria frutescens) which is native to the 

southeastern U.S. to southern Virginia, trumpet creeper (Campsis radicans), trumpet honeysuckle (Lonicera 

sempervirens), Dutchman’s pipe (Aristolochia macrophylla), and crossvine (Bignonia capreolata). Contact your local 

native plant society for information on sources of these and other native plants appropriate for your area. 

OTHER LINKS 

• http://www.invasiveplantatlas.org 

• http://www.invasive.org/eastern/species/3082.html 

AUTHORS 

Jil Swearingen, National Park Service, National Capital Region, Center for Urban Ecology, Washington, DC 

Tom Remaley, National Park Service, Great Smoky Mountains National Park, Gatlinburg, TN 

REVIEWERS

John Parrish, Phil Pannill 

PHOTOGRAPHS 

J. Scott Peterson, USDA NRCS PLANTS Database 

Bill Johnson, billjohnson (at) usinternet.com 

REFERENCES 

Gleason, H.A., A. Cronquist. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. 2nd ed. 

The New York Botanical Garden, p 910. 

Kartesz, J. 2010. Biota of North America Project. http://www.bonap.org/ 

Kaufman, S. R. and W. Kaufman. 2007. Invasive Plants: Guide to Identification and the Impacts and Control of Common 

North American Species. Stackpole Books, Mechanicsburg, PA. 458 pp. 

Invasive Plant Atlas of the U.S. 2010. The University of Georgia Center for Invasive Species and Ecosystem Health and 

the National Park Service. Available online at www.invasiveplantatlas.org/; last accessed March 30, 2010. 

Isely, D. 1990. Vascular flora of the southeastern United States. Volume 3, Part 2: Leguminosae. Chapel Hill, NC: The 

University of North Carolina Press, p 96. 

Radford, A.E., H.E. Ahles, C.R. Bell. 1968. Manual of vascular flora of the Carolinas. Chapel Hill, NC: The University of 

North Carolina Press, p. 1183. 

Rehder, A. 1993. Manual of cultivated trees and shrubs. Vol. 1. Dioscorides Press, Portland Oregon. p.507. 

Rhoads, A. F. and T. A. Block. 2000. The Plants of Pennsylvania, An Illustrated Manual. University of Pennsylvania Press, 

Philadelphia. 

Swearingen, J. 2009. Survey of Invasive Plants Impacting National Parks in the United States. 

http://www.invasiveplantatlas.org/parksurvey.pdf 

Thomas, L.K. Jr. 1993. Chemical grubbing for control of exotic wisteria. Castanea, 58(3):209-213. 
19 April 2010 Page 5 of 5 

Plant Conservation Alliance®s Alien Plant Working Group 

Xeeds HoneXild: Alien Plant Invaders of Natural Areas 

http://www.nps.gov/plants/alien/

USDA, NRCS. 2010. The PLANTS Database (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 

70874-4490 USA. 

Weakley, A. S. 2010. Flora of the Southern and Mid-Atlantic States. Herbarium of the University of North Carolina, Chapel 

Hill, NC. http://www.herbarium.unc.edu/WeakleyFlora2010Mar.pdf 

Zheng, H., Y. Wu, J. Ding, D. Binion, W. Fu and R. Reardon. 2005. Invasive Plants Established in the United States that 

are Found in Asia and Their Associated Natural Enemies, vol. 2. U.S. Department of Agriculture, Forest Health 

Technology Enterprise Team. FHTET 2005-15. p. 156.