Trouble With Butterfly Bush
The bush is 13 feet high, but for the last two summers it has not bloomed. This year it hasn't even greened, but there is life when you break a branch. What to do?
My mother always taught me to severely prune butterfly bushes. I prune mainly in the spring as I like to leave the seeds for the birds (mainly bush tits). I do prune throughout the growing season if it gets to gangly. Spring pruning should be drastic. You can prune right down to stubs say a foot or so high where new growth is showing. I normally don't do quite so much but I do prune at least to just a few feet high.
Hope this helps.