I have several viburnums which were planted last summer. They're about 2 to
3 feet tall and blooming nicely this spring. The fragrance is wonderful. I'm
not sure when or how much to prune them for maximum growth and flowering
next year. And will they branch out at the points where they are pruned?
They are in a somewhat shady area near the house and I don't want them to
become too spindly. Advice would be much appreciated!

I'm in Zone 6 if that matters.