Hi, I was wondering why sometimes the butterfly bushes (and this year hydrangeas also) only put out growth from the bottom and all the long stems are dead? I've had a butterfly bush for several years now that has been getting really big and most years growth sprouted from the previous years' branches. This year, though, I've had to cut all of mine practically down to the ground where the new growth is emerging. So not sure how the one (previously quite tall and full) bush will get. Most unusual to have to whack down the hydrangea stems so far. Is it due to a relatively mild winter with little precipitation? Or unusually cold temps very early spring that may have killed off buds that otherwise might have emerged? Thanks for any replies.