How to Prune rhododendron 'Arctic Tern'?
Usually little pruning is needed. Lightly shape if necessary, removing dead, damaged or diseased shoots. Prune after flowering. Remove spent flowers where practical.

rhododendron 'Arctic Tern' · Rhododendron 'Arctic Tern'
Also known as: ledodendron 'Arctic Tern'
Grow in moist but well-drained, leafy, humus-rich acid soil in part shade with shelter; see rhododendron cultivation
Usually little pruning is needed. Lightly shape if necessary, removing dead, damaged or diseased shoots. Prune after flowering. Remove spent flowers where practical.