American Wisteria is a woody, deciduous perennial vine that is not invasive like the Asian Wisteria. The blooms of cultivar 'Amethyst Falls' are said to be fragrant, but I find the scent rather unappealing. Here in my area the bloom time is extremely short, but I still enjoy the beauty of the flowers each spring.
Chinese Wisteria is indeed a beautiful flowering vine that can attain heights to 40 feet, with branches and stems 8 to 10 inches in diameter! The leaves of the Chinese Wisteria are wavy and tapered toward the tip. The fruit is a hairy, flat, approximately 6-inch-long pod that contains the seeds. Long, dangling panicles of very fragrant purple, white, or lavender flowers appear in spring.
I got 6 'Blue Moon' wisteria seeds from AudreyDee in the NFSR Swap Dec. 2018. I planted them 1-7-19 after I nicked & soaked them overnight. By the 19th (day 12) five sprouted & grew fast. Today, 1-29th, I transplanted the five plants that are already 5" & have several leaves into a little bigger pots. The 6th one just sprouted overnight. Pretty good odds getting 6 of 6 to germinate. I'm so pleased, AudreyDee!
American Wisteria is a Florida native, mostly limited to the panhandle area. This vine can climb 30 to 40 feet and has large, 4" to 9" long drooping clusters of numerous pea-like, 3/4 inch lilac to purplish flowers. The fruit of American Wisteria is a 2-5" narrow, smooth green pod that turns brown when mature. This woody, deciduous vine grows in habitats of moist areas, stream margins, swamps, and wet forests. American Wisteria is attractive to bees and the leaves are a host plant for caterpillars of the Long-tailed Skipper and Silver-spotted Skipper.
The Japanese Wisteria is occasionally found in Eastern and Midwestern landscapes in the US. It is a powerful, fast-growing woody vine (liana) that twines clockwise upon things. It blooms before the foliage emerges, with violet or blue-violet large grape-like clusters on old wood in April-early May. It is a very rampant vine that will kill trees if growing upon them and can break trellises or fences that are not strong, and it will grab anything. In USDA Zone 5 it often does not bloom because of late frosts. When it gets old it often does not bloom much, so gardeners often will give it super-phosphate and root prune to get it to bloom better. It has escaped cultivation in some areas. especially down South, and is invasive and a nuisance. There is a very similar Chinese species that should be considered a variety as the two can hybridize. The Chinese is supposed to leaf out a little later and climb counter-clockwise. They both can ground sucker and become quite a mess.
American Wisteria occurs infrequently in low open woods throughout much of the southeastern coastal plain area. It is not nearly as vigorous as the Chinese Wisteria which has escaped cultivation and festoons wild trees in our area, but it will still easily grow to 30 feet or more. White Wisteria has late spring and early summer flower clusters in 4 to 6 inch racemes of fragrant soft white. Grow this vine in full sun to light shade in average soil where you want the effect but perhaps not the strength of Chinese Wisteria. The white form is rare in the wild.
Found at Dam B (a lake in Southeast Texas) and introduced by Lynn Lowrey. A native wisteria that is not aggressive like its Asian relatives.
The Kentuck Wisteria was considered as a separate species classified as W. macrostachys, but in more recent times it is considered as a variety of the American Wisteria (W. frutescens). This Kentucky Wisteria (W. frutescens macrostachys) has its pea-like flowers in more spike-like 8 to 12 inch raceme clusters and its compound leaves have about 9 leaflets and its pods are a little longer of 3 to 5 inches and are often twisted. The American Wisteria has its pea-like flowers in a more compressed raceme flower cluster of 4 to 6 inches long with 9 to 15 leaflets, and pods about 2 to 4 inches long. This cultivar of 'Clara Mack' has white flowers instead of lilac purple and was introduced to the nursery trade by Woodlanders in Columbia, South Carolina and named after a gardener in that city.
