Prune after bloom. That particular growth form does not do well with what you propose. Proper pruning is required. Removing entire canes is the proper procedure for that growth form.

Dan

Thank you, i am so glad I asked. Its in full bloom right now.

All the bloom is on new wood, and many people prune it before the bloom and lose a season. It is a rampant grower and I prune mine pretty hard,taking the oldest canes down to the ground. If done after the bloom the shrub has all summer to produce next years blooming canes. Al