How to prune butterfly bush 'black knight'

Early spring, as soon as frost risk passes and before new growth extends. Cut all woody stems back hard to 12–18 inches above ground level using loppers. Remove any dead or crossing stems at the base. Deadhead spent flower spikes throughout summer to encourage further flushes of bloom.

Annually (hard spring prune); deadhead throughout summer. Butterfly Bush 'Black Knight' blooms on current-season wood and needs hard annual pruning in early spring to stay compact and flower well. Left unpruned it becomes leggy with poor bloom. Cut all stems back to 12–18 inches from the ground each spring for the best results.

Cut all woody stems back hard to 12–18 inches above ground level using loppers. Remove any dead or crossing stems at the base. Deadhead spent flower spikes throughout summer to encourage further flushes of bloom.