Native to North America, this variety (Wisteria frutescens) can still reach up to 30 feet in height and width, showering any nearby structure in clusters of mesmerizing blue flowers. However, you may have to wait five or six years for the vine to mature and produce flowers. It has pinnate, shiny, dark leaves and pea-like flowers that hang in clusters about 5 to 6 inches long. After flowering, American wisteria creates smooth, bean-like seed pods. With a more controlled manner of growing, American wisteria offers the perfect solution for many who long for this plant’s stunning flowers in their own garden. While not considered invasive, this plant’s fast-growing nature means it may be better if grown in an isolated area. Otherwise, it may choke out neighboring plants. Regular pruning can encourage more flowering, which may easily stretch from spring into the summer. This is another advantage of American wisteria, as its Chinese cousin only blooms once in the spring. American wisteria is deer-resistant and flood-resistant.
Light
American wisteria loves the sunshine and grows best in full sun. It can be grown in partial shade, but these conditions may not allow the plant to bloom as profusely. Plenty of sunlight is essential for healthy flowering.
Soil
Rich, moist, well-draining soil is ideal for this vine. Acidic to neutral pH levels are best. Soil that is too alkaline can cause these plants to become chlorotic, which means the leaves do not produce enough chlorophyll. The leaves will lose their green color and turn a dull shade of yellow.
Water
American wisteria is naturally found in moist areas by rivers, swamps, or flood plains. Therefore, this vine thrives on consistent moisture. Maintain a regular watering schedule, especially during hot summers when soil may dry out more quickly.
Temperature and Humidity
American wisteria plants prefer moderate moisture levels but can tolerate high levels of moisture and humidity. It does best in moderate climates, as indicated by its suitability for USDA hardiness zones 5 to 9.
Fertilizer
Adding fertilizer will encourage blooming, which may take up to five or more years to occur. Be sure that your fertilizer contains a good amount of phosphorus, as this will help encourage blooming. Beware of fertilizer that is high in nitrogen.
American Wisteria Varieties
‘Nivea’: This variety produces short clusters of white flowers. Its main bloom appears in the summer, but this vine is known to sporadically bloom afterward. ‘Amethyst Falls’: As suggested by the name, Amethyst Falls produces beautiful purple flowers with a light fragrance. This variety blooms at a younger age, making it a good choice if you’re in a hurry for a flowering wisteria plant. ‘Alba’: Another variety with white blooms, Alba produces large white flowers in short, full clusters.
Pruning American Wisteria
This plant only flowers on wood that was produced the previous growing season (one-year-old wood). It’s thinner, lighter in color, and more flexible than older wood. Be careful not to remove all the flowering wood when pruning. Regular pruning is key to keeping your large vine full of blooms. Prune the vine twice each year: once before the plant leafs out in the spring, and again just after flowers fade. After blooming in the summer, cut back that year’s growth to around 6 inches. This will help control the vine’s growth, as well as encourage thick blooming.
Propagating American Wisteria
Using cuttings is the best way to propagate wisteria. Seeds can also be used, but these take years to mature and flower which makes cuttings the quickest and most ideal way. Be sure to take cuttings from softwood, which is wood that is still green and has not developed woody bark. Annual pruning is a perfect time to propagate. Instead of tossing pruned stems, you can propagate a new plant with them.
