Kate, Welcome. First, your butterfly bush: It is normal for them to die back to the ground level or thereabouts over the winter in colder zones, and what you do each year is wait till you see the first signs of life and then cut back all the old stems about that point, usually just above the base. So you didn’t do anything wrong or get a loser! As for the "snowball bush" I am wondering if it is the white hydrangea called ‘Anabelle’ perhaps? Look at this link and tell me: http://www.hydrangeashydrangeas.com/annabelle.html With the blue hydrangeas, you will soon know if those are new stems growing up from the roots, so give it a little time and see what develops. Sounds like even if they are hydrangea shoots you will skip a year of bloom while it grows in. Generally blue moptops like that are pruned right after bloom, removing the oldest stems at the base to make room for new ones…but yours (if they make it) won’t need any pruning anytime soon. Probably good to separate questions as you suggest into different areas in the future, yes, and thanks. M.