Pruning is the answer, in my opinion, but you need to know how you want to to grow.

For example, Forsythia is a much maligned plant. People think that they should be left on their own, are garden hogs, or are difficult to maintain.

False, false and false.

The pic shows a 50 year old plant. Shortly after it blooms, I trim it down to 1' from the base. (2' if you want a larger plant next year) and that is all you need do.

This year's growth will produce the long strands to make it a spray of color in the spring.

Orange Emperor tulips are a good extra. 20 more will be added this week!

Most plants can be persuaded to put on a nice performance. Learn when to trim without causing winter damage or from losing a bloom. Where there are cold winters, NEVER trim a plant in the fall as it stimulates growth that will die in the winter.

This web site needs a "How to Trim Perennials, Bushes and Trees" forum.

Anything named "Winterthur" has good PR going for it, but your Blackhaw is probably more unusual and definitely lovely, so don't let anyone malign it. Enjoy it!

IMO some viburnums do not respond well to pruning, so take care. Their wood is very strong and they put much effort into building it. Some react by making very angular branching that is difficult to deal with, and some, such as the doublefile viburnum, have a distinct growth habit that is part of their charm and utterly destroyed by pruning.

Yes! A forum on pruning would be so helpful. Actually, maybe just a pruning and trimming channel on YouTube. I love abelias (5 in my tiny urban front yard, including a Chinese abelia), but I have had to teach myself how to prune them through trial and error.

Thanks for the advice on the Blackhaw viburnum. I was already puzzling how to train it into a tree form. I read that you should only prune the dead branches on Blackhaws. But I will have to cut some of the low lateral branches if I want a tree form.

"Yes! A forum on pruning would be so helpful. Actually, maybe just a pruning and trimming channel on YouTube."

YouTube does not allow discussion and many videos there are just plain wrong factually.