The fragrance of many viburnums is a sweet, delicious addition to their attractive flowers and beautifully ridged leaves. They rarely need any pruning besides the removal of damaged branches, but as they age, it may be necessary to control the size of the shrub. Follow a few simple guidelines to help you prune without damaging either its shape or its future blossoms.
Choose Your Cuts Wisely
First, decide when to prune. Viburnum flowers open in spring from buds that are formed the previous summer, so if you prune later than the end of June, you'll be cutting off the next year's blossoms. May is ideal, though any time from the end of bloom through the middle of June will work.
Next, imagine the changes you want to make in your shrub. Is it too tall? Is it too wide? Too dense? Too close to the wall of the house? The more clearly you imagine the results of your cuts, the more skillfully you can place them.
Now, using your lopper, prune any stems that are too tall all the way to the ground. Cutting back part way forces growth out at awkward angles that spoil the shape of the shrub. When older, taller shoots are removed completely, a more open but still graceful framework is left behind.
Finally, using sharper pruners, remove any branches that extend too far to the side by cutting them off at their base, at the trunk they sprouted from. Again, cutting them off part way will force out new growth at unattractive angles.