I've been agonizing over my Double File viburnums for years. They simply do not, and have never, looked the way they are supposed to look. I can send a photo or video of them. I trim them every year based on advice I've read online. I cannot seem to control the vertical branches from forming on the horizontal branches. It seems like every time I prune a vertical branch, it causes new verticals to grow from the pruned horizontal branch. My viburnums look like big messy shrubs. I am at my wits end with these bushes, but they are major elements in my landscape. I can't afford to have a landscape designer/horticulturalist look at them, so I really need your help. I believe sending you a photo or a video will give you more of an idea on the problem.
Double File Viburnum
Certified GKH Gardening Expert
I will say that sometimes plants, like people, just don't react the way they are suppose to. It is ok to experiment as little (or a lot) to see if you can find a pruning technique that works for you. We will be happy to help you with that.