Wisteria frutescens 'Amethyst Falls' Perfect for smaller spaces, this gorgeous twining vine grows at about a third of the rate of Asian wisteria. Blooms at an early age, with its lightly fragrant purple racemes weeping gracefully downward.
Annual flowers are shallow-rooted and benefit from frequent watering, especially in the first four to six weeks after being planted. Water them every two to three days when rain doesn't happen – or whenever the top few inches of soil is dry when you insert your index finger.
Fertilize your wisteria with a low-nitrogen product once every year, or every other year. Nitrogen fertilizing does encourage growth (but remember: not too much nitrogen!), so this is a critical step.
Summer pruning (July or August) Cut back the whippy green shoots of the current year's growth to five or six leaves after flowering in July or August. This controls the size of the wisteria, preventing it getting into guttering and windows, and encourages it to form flower buds rather than green growth.
