Wisteria Tree Plant

Wisteria flowers

The Wisteria Tree, or Wisteria sinensis, is a temperate-region climbing vine of the pea family, cultivated for its abundant and fragrant blue flowers and attractive climbing habits. Wisteria vines are fast growing and can form impressive displays of flowers all around a house or pergola. Wisteria sinensis can be distinguished from the similar Japanese species Wisteria floribunda by its larger flowers and smaller flower racemes.

Classification

Wisteria sinensis is one of 10 species in the Wisteria genus that are distributed across East Asia in China, Japan and Korea as well as in the U.S. Hybrids between different species, especially between W. sinensis and the Japanese Wisteria W. floribunda are common in cultivation. As members of the pea or Fabaceae family, Wisteria vines are able to fix their own nitrogen, thanks to a symbiotic relationship with bacteria.

Identification

Wisteria leaves are pinnate and up to 15 inches long with up to 13 leaflets. The fast growing stems twist corkscrew-like and can be 50 feet long. The flowers grow in hanging or pendulous bunches or racemes up to 30 inches long and can be blue, purple, pink or white. The flowers are followed by flattened velvety pods containing poisonous, disk-like seeds. Wisteria sinensis is deciduous and the flowers appear on the bare vines in spring before the leaves.

Range

Wisteria sinensis originates in China but is now cultivated all over the temperate and subtropical world. It was introduced into the U.S. in 1816. Floridata notes that the Chinese Wisteria is on the list of Florida invasive species and recommends that Floridians cultivate the less spectacular and more finicky American species Wisteria frutescens. According the the National Parks Service, Wisteria sinensis is considered an invasive species in 19 U.S. states.

Cultivation

Wisteria sinensis grows best in USDA Zones five to nine and is frost-tolerant. Wisteria vines favor rich but well-drained soils and need to be planted in full sun or partial shade. Vines will climb up and over any available structure and can smother less vigorous species. Prune back new growth to train young Wisteria vines into a self-supporting tree-like shape. Wisteria vines can live for over 100 years.

Caution

As well as being invasive in some areas, Wisteria vines are very difficult to remove from a garden once they're established, as even a small piece of root will regrow. Wisteria vines will outgrow and strangle most other vines and trees if they are allowed to grow over them unchecked. Wisteria vines will also damage guttering and other structures.
Wisteria plants contain the toxic glycoside wisterin which can cause gastroenteritis if swallowed.

References

• Floridata: Wisteria sinsensis
• Arbor Day Foundation: Hardiness Zone Map
• National Park System: Chinese Wisteria