Wisteria floribunda, the Japanese wisteria, is a woody liana of the Wisteria family. It was brought from Japan to the United States in 1860 by George Rogers Hall. Since then, it has become one of the most highly romanticized flowering garden plants. It is also a common subject for bonsai, along with Wisteria sinensis (Chinese wisteria).
The flowering habit of Japanese wisteria is perhaps the most spectacular of the Wisteria family. It sports the longest flower racemes of any wisteria; they can reach nearly half a meter in length. These racemes burst into great trails of clustered white, violet, or blue flowers in early- to mid-spring. The flowers carry a distinctive fragrance similar to that ofgrapes. The early flowering time of Japanese wisteria can cause problems in temperate climates, where early frosts can destroy the coming years’ flowers. It will also flower only after passing from juvenile to adult stage, a transition that may take many frustrating years just like its cousin Chinese Wisteria.
Japanese wisteria can grow over 30m long over many supports via powerful clockwise-twining stems. The foliage consists of shiny, dark-green, pinnately compound leaves 10–30 cm in length. The leaves bear 9-13 oblong leaflets that are each 2–6 cm long. It also bears numerous poisonous, brown, velvety, bean-like seed pods 5–10 cm long that mature in summer and persist until winter. Japanese wisteria prefers moist soils and full sun in USDA plant hardiness zones 5-9. The plant often lives over fifty years.