Plants that bloom in summer, such as potentilla, butterfly bush, and crape myrtle, produce their flowers on new growth from the current season. Prune them in winter while they're dormant, or in early spring just before they push out their new growth
Pruning butterfly bush: We all know the importance of pruning shrubs and trees. While it has been said that improper pruning practices result in weakened or damaged plants, this is not the case with the butterfly bush. Read here to learn more.
Butterfly Bush Care – How To Care For A Butterfly Bush