Soft pink flowers open in early summer, weeks after most rhododendrons have finished, which stretches the season at the back end. Rhododendron maximum 'Roseum' is a selection of a native evergreen, growing 6 to 8 feet tall and 8 to 10 feet wide in part shade, hardy from Zone 4 through Zone 8.
The trusses sit above large leathery evergreen leaves that curl tightly downward in hard cold, which is normal behavior and not a sign of trouble.
Rosebay is the rhododendron that grows in the shade of mature woods rather than needing the edge of them, and it spreads wider than tall, filling horizontal space as a screen or an understory planting.
It grows wild in cool moist woodland ravines and along mountain streams, so it wants acidic soil rich in organic matter and steady moisture. It struggles in dry ground, alkaline soil, or full afternoon sun. Mulch matters, since the roots sit shallow.