How to prune korean rhododendron

Immediately after flowering (late winter to early spring). Cut spent flower stems back to a strong sideshoot or dormant bud. To reduce legginess, cut one or two oldest stems back hard to near the base each year after bloom, encouraging new basal shoots. Avoid topping the plant.

Annually after flowering; harder renewal cutting every 3-5 years. Korean rhododendron (R. mucronulatum) is a deciduous flowering shrub that blooms very early — late winter to early spring — before leaves emerge. Prune immediately after flowering before leaves fully unfurl. Remove dead or damaged wood and lightly shape to prevent legginess. Do not prune in summer or autumn, or you will remove next season's buds.

Cut spent flower stems back to a strong sideshoot or dormant bud. To reduce legginess, cut one or two oldest stems back hard to near the base each year after bloom, encouraging new basal shoots. Avoid topping the plant.