Royal azalea (Rhododendron schlippenbachii): when and how to prune

Royal azalea (Rhododendron schlippenbachii): when to prune it?

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It needs little pruning. Do it just after flowering, in May–June, because next year’s flower buds form in summer.

What else to prune in those months? May · June

Royal azalea (Rhododendron schlippenbachii): how to prune it?

1. Snap or cut off spent flowers if you wish.
2. Remove dead, weak and crossing branches at the base.
3. Shorten overlong branches just above a side shoot to adjust the shape.
4. An old, bare shrub can be cut back to 30–50 cm above the ground in March: it usually regrows, but will not flower that year.

How much to cut, and how often?

• One pruning period a year: May–June.
• Prune in moderation: never remove more than about a third of the shrub at once.

What does it mean for wildlife?

• Pruning in May–June can fall in the nesting season (15 March–15 August). Check carefully for nesting birds first: disturbing an active nest is against the law.
• Royal azalea (Rhododendron schlippenbachii) flowers in April–May, when it attracts bees.
• If pruning falls during flowering, wait until it is over or leave part of the plant to flower, so bees and butterflies still benefit.
• Prunings can go on a dead hedge or brash pile in a corner of the garden: shelter for hedgehogs, wrens and insects.

Common mistakes

• Clipping without first checking for nesting birds.
• Leaving a stub or sawing flush with the trunk: cut just outside the branch collar.

Nearby: related pruning guides

• Rhododendron
• Dwarf rhododendron (Rhododendron impeditum)
• Flame azalea (Rhododendron calendulaceum)
• Rhododendron (Rhododendron williamsianum)
• Torch azalea (Rhododendron kaempferi)
• Western azalea (Rhododendron occidentale)

Plant profile: Royal azalea (Rhododendron schlippenbachii) · Pruning calendar and basic rules