Q: Last fall I cut my butterfly bush back to eight inches and it grew six feet high this year. It was beautiful but it shaded all the other flowers I planted around it. Is there any way I can prune it so it won’t grow quite so big?
A: Butterfly bush is a great plant, but all to often it becomes a great big plant before you know it. There is really no way to keep it as small as you want it to be. Constant pruning would remove the flowers you expect from it.
Common butterfly bush cultivars reach ten feet high and wide if unpruned for a couple of years. The Nanho series (‘Nanho Blue’, ‘Nanho Purple’, ‘Nanho White’) are sold as dwarf forms but they can easily grow to six feet tall. You have two choices: move the flowers or move the bush.