Can Rhododendrons be cutback severely to 4 feet tall without harming them?
A. Healthy rhododendrons are tolerant of the kind of severe pruning you are contemplating. Although you normally prune them when they finish blooming, severe pruning is best done in late March. You will sacrifice next year’s flowers. Rhododendrons bloom on old wood, which means that they set flower buds for next year as soon as they finish blooming this year. If you prune after the buds are formed, you remove the following season’s flowers. The type of severe pruning you want to do is stressful to the plant, and is best done before they bloom. That way, the rhododendrons can put their energy to re-growth and recovery rather than flowering.
