Butterfly Bush – Safe Pruning
Q: I have a butterfly bush that is overgrown. When is it safe to prune it back and how far?
A: You can cut back the butterfly bush anytime after the first killing frost. It will undoubtedly still have leaves on it but you can remove everything above eighteen inches from the ground. This will stimulate the plant to put out vigorous new growth in April and fragrant blooms will appear for the rest of the summer.