Wisteria encompasses four species, three from eastern Asia and one native to North America, all sharing the same intoxicating quality in bloom: long, drooping clusters of fragrant flowers in spring that can stop a garden visitor mid-step. The genus was named for Caspar Wistar, an eighteenth-century Philadelphia physician, and the plants have been moving through Western gardens ever since. They adapt readily to most soils and moisture conditions, but they flower best in full sun and respond poorly to neglect.

The pruning requirement is the bargain you make with this plant. Twice a year keeps it manageable and productive: a cutback in midsummer after flowering, trimming long shoots to five or six leaves, and then a harder cut in January or February to two or three buds. This two-stage approach builds the flowering spurs that deliver next spring's show. The Asian species, particularly Chinese and Japanese wisteria, are invasive in many parts of the eastern United States and should not be planted near natural areas. The American species, Wisteria frutescens, offers most of the beauty with far less of the aggression.