Wisteria frutescens 'Amethyst Falls' (American Wisteria)Earlier to bloom and less aggressive than non native forms of Wisteria, use this 15 20' tall Eastern U. S. native cultivar in their place. Lavender purple racemes appear in late spring and blooms continue sporadically through summer. Prefers humus rich, well drained soil. Full sun will promote heavier flowering. Plant 10' apart. Sunlight Requirements: Full Sun to Partial Shade USDA Hardiness Zones: 4 9