As soon as their flowers fade, it’s time for azalea, rhododendron, chokecherry, lilac, weigela, forsythia, and viburnum pruning. These spring-blooming shrubs produce their flowers on the previous year’s growth. Pruning them too late in the season could mean accidentally removing next year’s developing flower buds. If you are unsure of when to prune a particular flowering shrub, a good rule of thumb is always to prune immediately after flowering.
Whether you’re doing a heavy viburnum pruning or a light shaping of your rhododendrons, proper pruning promotes well-branched shrubs with a denser growth habit.
Tips for spring-blooming shrub and viburnum pruning:
- You shouldn’t prune spring-blooming shrubs into round meatball shapes. Instead, start by removing any dead branches, and then selectively trim others, one-by-one, in order to maintain the shrub’s natural shape.
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- Use a clean, sharp pair of pruners or a small pruning saw to make the cuts. To prevent the spread of disease, disinfect the blades with a spritz of pruning disinfectant before you move to another plant.
- The pruning requirements of spring-blooming shrubs are minimal because their natural growth habit requires very little maintenance.
- Don’t remove more than one-third of the total plant height at any one time, and step back and carefully examine the plant after each cut.
- Keep the shrub’s structure open by removing one or two of the larger branches each season. This also encourages new growth.
Viburnum pruning, and the pruning of other spring-blooming shrubs, isn’t hard, but it does require a bit of finesse. With a light, yearly pruning that encourages their natural form, these plants will produce a plethora of beautiful blooms every spring.
Mock orange, too!
Annie Bayer says
Can viburnums be pruned in the fall and if so, how late into the fall can they be pruned?
Jessica Walliser says
They can be pruned in the fall, but doing so will remove the flower buds for the following season. If you’re willing to sacrifice a year’s flowers, you can prune soon after the leaves drop from the plant.