Would it be OK to trim off the branches of my ninebark that have grown so much taller than the rest of the plant? I realize these are the new growth branches but the shrub looks rather unsightly with the tall stragglers on top. It’s July.
Ninebark wants to make long arching branches. That is its natural form. If you want to fight with mother nature, prune right after bloom. It won't kill the shrub to prune now but pruning does spur more growth. That new growth may not be able to harden off before winter arrives. Late pruning also sacrifices some of next year's bloom. Are you removing 20-30% of the oldest wood annually? Ask yourself if the shrub is in a big enough location to grow naturally. If not, you will have an on-going irritant as you try to keep it in place. In early spring before leaves emerge, you can cut it down and transplant to a larger area, if necessary.