How to Prune Viburnum Trilobum

Prune your Viburnum trilobum just after it flowers in the spring. This promotes vigorous growth through the summer and results in more flowers the next spring.

Cut out any injured, dead or diseased foliage as quickly as possible. According to the Missouri Botanical Garden, Viburnum trilobum is somewhat susceptible to stem blight, powdery mildew and bacterial leaf spot. This bush has dense foliage, so it is important that you inspect the inner branches for any problems.

Prune diseased branches back until you get to healthy, green wood. If you must remove an entire branch, cut the limb just outside of the branch collar and not flush with the trunk.

Give your American cranberry bush regular maintenance pruning if you use it as a hedge. Prune newly planted hedge plants to within 1 foot of the soil. Trim off any new shoot tips during its first growing season to promote branching.

Give your Viburnum trilobum a hard pruning only if it becomes overgrown. Make thinning cuts to remove the older, bigger stems at the bush's base. Use pruning shears on smaller branches, but cut thicker limbs with hedge clippers.

Prune out the oldest limbs on older Viburnum trilobum shrubs. Thinning out the older, larger limbs encourages new plant growth and makes your bush look fuller, younger and healthier.

Cut out center branches to increase air circulation toward the middle of the bush. This helps minimize the risk of your plant contracting serious diseases. Remove any inner branches that touch or cross each other to decrease the chance of wood injury.