Learn what you need to know to tackle viburnum pruning with confidence.
Grow a viburnum, and you don’t have to worry about doing a lot of pruning. Viburnum pruning is not an annual task, unless you’re growing a young plant that you’re pruning to a tree shape. Otherwise, pruning viburnum is a chore you tackle at specific times in the life of the plant. How to prune viburnum really depends on what you want to accomplish with a plant. The same is true of when to prune viburnums — timing depends on your goal.
One reason to consider pruning viburnum is to create a hedge. Not all viburnums are suited for hedging, but Viburnum odoratissimum is. This viburnum, including the variety Viburnum odoratissimum ‘Awabuki,’ adapts well to heavy pruning. In some areas of Florida, this viburnum is used to create thick privacy hedges between neighborhoods and busy traffic zones.
When pruning viburnums to create a screen, cut immediately after flowering and again in midsummer. This may sacrifice the fruit show, but it will enable plants to form flower buds for the following year. This timing of when to prune viburnum — immediately after flowering — is pretty standard for the group.
If you’re pruning viburnums to restrain or shape their growth, the timing for when to prune viburnum is right after flowering. Viburnums typically form their flower buds for the following year during the summer after flowering. If you wait to prune viburnums in fall or early spring, you risk cutting off flower buds. Pruning viburnums after flowering does reduce fruit formation, so you want to prune only when absolutely necessary.
One part of how to prune viburnum has to do with timing — when to prune viburnum. Another part has to with the goal of viburnum pruning. With viburnums like Viburnum bodnantense and Viburnum burkwoodii, two fragrant viburnums that flower in early spring, you can prune to create a viburnum tree. These viburnums both produce multi-stem trunks, so to produce a tree viburnum, you need to choose one trunk for the main one and remove the rest, along with lower branches as they form.
Another pair of viburnums that benefits from pruning are Viburnum ‘Chindo’ and Viburnum awabuki. Prune these viburnums in late winter to aid plants in growing uniformly through the growing season. You can also do a midsummer pruning to keep these fast growing viburnums from getting out of hand.
Viburnum pragense is an evergreen viburnum that occasionally drops its leaves during a cold winter. When this happens, pruning is your tool of choice to rejuvenate the plant. When to prune Viburnum pragense after a hard winter is after new growth starts appearing. If no new leaves appear on stems, wait another week or two before pruning. If no leaves appear, cut stems to ground level. New growth will sprout from the roots.