Wisteria flower.

Wisteria (also spelled Wistaria) is a genus of flowering plants in the pea family, Fabaceae, that includes 10 species of woody climbing vines native to the eastern United States and the East Asian states of Japan, China, and Korea. Aquarists refer to the species Hygrophila difformis, in the family Acanthaceae, as Water Wisteria.

Wisteria vines climb by twining their stems either clockwise or counter-clockwise round any available support. They can climb as high as 20 m above ground and spread out 10 m laterally. The world’s largest known Wisteria vine is located in Sierra Madre, California, measuring more than 1 acre (0.40 ha) in size and weighing 250 tons.

The leaves are alternate, 15 to 35 cm long, pinnate, with 9 to 19 leaflets. The flower are produced in pendulous racemes 10 to 80 cm long, similar to those of the genus Laburnum, but are purple, violet, pink or white, but not yellow. Flowering is in the spring (just before or as the leaves open) in some Asian species, and in mid to late summer in the American species and Wisteria Japonica. The flowers of some species are fragrant, most notably Chinese Wisteria (Wisteria Sinensis). The seeds are produced in pods similar to those of Laburnum, and, like that genus, are poisonus.

Wisteria Japonica.

Chinese Wisteria (Wisteria Sinensis).

There are two noted attributions for the name Wisteria. One, that the botanist Thomas Nuttall named the genus Wisteria in honour of Dr. Caspar Wistar (1761 – 1818) — some call it Wistaria but the misspelling is conserved under the International Code of Botanical Nomenclature. The other, that the genus was named after Charles Jones Wister, Sr., of Grumblethorpe, the grandson of merchant and wine importer John Wister. Daniel Wister, Charles’s father, joined with Samuel Miles and Rober Morris to underwrite the voyage of the American commercial vessel Empress of Chine. On board the ship was the vine that would later bear the Wister name.

Wisteria species are used as food plants by the larvae of some Lepidopteraspecies including brown-tail. It is also an extremely popular ornamental plant in Japan and China.


Wisteria, especially Wisteria sinensis, is very hardy and fast-growing. It is considered an invasive species in certain areas. It can grow in fairly poor-quality soils, but prefers fertile, moist, well-drained ones. It thrives in full sun to partial shade.

Wisteria can be propagated via hardwood cutting, softwood cuttings, or seed. However, seeded specimens can take decades to bloom; for that reason, gardeners usually grow plants that have been started from rooted cuttings or grafted cultivars known to flower well. Another reason for failure to bloom can be excessive fertilizer (particularly nitrogen). Wisteria has nitrogen fixing capability (provided by Rhizobia bacteria in root nodules), and thus mature plants may benefit from added potassium and phosphate, but not nitrogen. Finally, wisteria can be reluctant to bloom because it has not reached maturity. Maturation may require only a few years, as in Kentucky Wisteria, or nearly twenty, as in Chinese Wisteria. Maturation can be forced by physically abusing the main trunk, root pruning, or drouhgtstress.

Wisteria can grow into a mound when unsupported, but is at its best when allowed to clamber up a tree, pergola, wall, or other supporting structure. Whatever the case, the support must be very sturdy, because mature Wisteria can become immensely strong with heavy wrist-thick trunks and stems. These will certainly rend latticework, crush thin wooden posts, and can even strangle large trees. Wisteria allowed to grow on houses can cause damage to gutters, downspouts, and similar structures. Its pendulous racemes are best viewed from below.

Wisteria flowers develop in buds near the base of the previous year’s growth, so pruning back side shoots to the basal few buds in early spring can enhance the visibility of the flowers. If it is desired to control the size of the plant, the side shoots can be shortened to between 20 and 40 cm long in mid summer, and back to 10 to 20 cm in the fall. The flowers of some varieties are edible, and can even be used to make wine. Others are said to be toxic. Careful identification by an expert is strongly recommended before consuming this or any wild plant. (Source: Wikipedia).