Amethyst Falls Wisteria Wisteria frutescens ‘Amethyst Falls’ Strong grower, but not invasive like its Asian cousins. This variety is less vigorous and easier to manage, refraining from choking out trees over time, as some Wisteria do. It flowers sooner, blooming its first season with fragrant, vividly blue flowers in the spring and repeat all summer. Deer, and drought tolerance. Disease-resistant foliage.