American wisteria is a woody vine with deciduous pinnately compound leaves usually less than a foot (30 cm) long. A leaf has 9-15 leaflets, each about 1-3 in (2-8 cm) long. The vine climbs by twining (no tendrils or root hairs), and manages to get quite high up in trees and shrubs; the vine can reach up to 50' (15 m) in length. Like its better known relative, Chinese wisteria (Wisteria sinensis), the American species produces purplish blue pealike flowers in racemes (clusters with all the individual flowers carried on a single axis). But American wisteria blooms later - after its leaves come out; its flowering racemes are shorter - only about 6 in (15 cm) long; and the pods of American wisteria are smooth rather than pubescent. There have been a few cultivars named: 'Magnifica' has purple-blue flowers with a big yellow blotch; 'Nivea' has white flowers.
Location Wisteria frutescens occurs naturally on the southeastern U.S. coastal plain from southeastern Virginia to central Florida and west to eastern Texas. Look for American wisteria in moist thickets around streams, ponds and swamps, usually clambering across shrubs and frequently climbing on fences.
xxx Light: American wisteria performs best in full sun, but tolerates partial shade. You'll get more blooming from plants grown in full sun. Moisture: Water regularly until established. Thereafter American wisteria should not require supplemental watering. Hardiness: USDA Zones 6-9. Propagation: Cuttings taken from side shoots can be rooted. Your odds are improved with bottom heat.
The American wisteria cultivar 'Magnifica' has flowers with vibrant violet-blue petals decorated with a handsome bright yellow-green splotch.
The Chinese wisteria is way too agressive for most homeowner landscapes. Use the native American wisteria where you want a climbing vine in smaller gardens. I have one growing on the chicken wire fence that encloses my vegetable garden, and another trained up a big live oak. My next project is to try and train one to a formal standard by pruning the leading shoot to just 3-4 ft (90-120 cm) long, cutting back the lateral shoots to a foot or two (30-60 cm), and cutting back the sublaterals to two or three buds, and doing this several times a year. In a couple years I should have a little American wisteria tree.
Unlike Chinese wisteria, American wisteria may bloom sporadically through the summer if conditions are favorable. American wisteria is a host plant for several species of butterflies, including the long-tailed skipper, for example. Native bees frequent the flowers.