A Wisteria species, native to the wet forests and stream banks of the southeastern United States, Wisteria frutescens, of which 'amethyst Falls' is an outstanding selection, is less vigorous than its Chinese counterparts, Wisteria sinensis, and is so perhaps better suited to smaller gardens, or even keeping in a well maintained pot (regular feeding and watering, please!).
Amethyst Falls is also notable reliabey in flowering from an early age, putting on a sumptuous display of light lilac-mauve, indeed, amethyst-coloured flowers with a fragrance which whilst recognisably is that of wisteria is also distinctly sweeter and more floral than W. sinensis.
Plant in a sunny or lightly shaded position in rich and fertile soil, and be ready to carry out regular pruning - the easist system of which is to cut back to two buds away from ripened wood towards the end of September. Some authorities will recommend two cuts, one in spring and in late summer - the RHS have some great videos on wisteria pruning which are readiliy available on line.
Fully hardy, Wisteria 'Amethyst Falls' can be trained on to the side of the house, or over a pergola and will in time form a wonderful, show-stopping plant that will give many years of joy. Unpruned, the final height may be as much 5m with a spread of some 3m.