Answer: You're located in the northern limits of Rose of Sharon's growing zone, so perhaps it's still a bit cool for this heat-loving shrub to be leafing out. If the buds are swelling, then new growth is imminent.
Your Rose of Sharon is probably still small if you just planted it in the fall, so you shouldn't have to prune it for a couple of years, except to remove damaged/diseased/broken/rubbing branches. When it is more mature, you can remove 1/3 of the branches in late winter/early spring, while the shrub is still dormant. Flowers appear on new wood in June and should continue to appear throughout the summer. Enjoy!
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