Prune butterfly bush in late winter or early spring before new growth starts
Cut back all stems to about 12 to 24 inches above the ground
Remove dead, damaged, weak, or crossing branches
Make cuts just above healthy buds or leaf nodes
Thin crowded stems to improve airflow
Remove spent flower spikes during the growing season to encourage more blooms
Use clean, sharp pruning shears or loppers
Disinfect tools before and after pruning
Dispose of pruned material properly
Avoid pruning too late in the season
Do not cut into old woody stems unless needed to shape or rejuvenate the plant