How to prune wisteria 'amethyst falls'

Summer (July–August after flowering) and again in late winter (January–February). Summer: cut all new whippy shoots back to 5–6 leaves from the main framework. Winter: cut those same shoots back further to 2–3 buds from the base to form flowering spurs. Tie in stems you want to extend the framework; shorten all others.

Twice yearly (summer + winter). Yes — Wisteria 'Amethyst Falls' requires a strict twice-yearly pruning regime to control vigorous growth and concentrate energy into flowering spurs. Without pruning it becomes a tangled mass with few blooms. The two-cut system (summer + winter) is essential and keeps this vigorous climber manageable on pergolas and fences.

Summer: cut all new whippy shoots back to 5–6 leaves from the main framework. Winter: cut those same shoots back further to 2–3 buds from the base to form flowering spurs. Tie in stems you want to extend the framework; shorten all others.