Reaching 30 feet or more, this wisteria, like other wisteria, is a strong grower, though not a runaway presence like some others can be. This native variety is less vigorous and easier to manage, but retains all the beauty of its less restrained cousins.
'Amethyst Falls' flowers younger than the Asian species, blooming its very first season with fragrant, vivid blue flowers in 4- to 6-inch clusters that appear in spring and repeat all summer. Arriving about two weeks later than those of other wisterias, the blooms manage to avoid late spring frosts.
It is also unpalatable to deer and other nibbling creatures, making it a good choice for open settings such as woodland and meadow gardens. Once established, it is quite tolerant of dry conditions, and it loves heat and humidity. Winner of several awards for its healthy green foliage, it is a lovely presence from spring through fall.
Find a strong support on which to grow this vigorous vine. Unless you prune it to keep it small (which it is happy to have you do), it will quickly grow and spread. Blanket outbuildings, unsightly fences, stumps, and other garden structures with it, or show it off on an arbor, pergola, or even a strong trellis.
'Amethyst Falls' can also be pruned into "tree" form by staking it young to a post or pole. Trim all but the central stem, and prune the lower branches to encourage it to grow straight upwards with a "trunk" and a canopy of branches and blooms at the top.
Regular annual pruning is best in late winter. Another light trim after the first flush of flowers will improve branching and may even stimulate a second season of flowers.
