Rhododendron 'Rothenburg' features open, bell-shaped flowers measuring 2½" to 4" wide, showcasing a pale yellow-green hue accented by deep yellowish-pink spots in the dorsal throat. Its dense, spherical clusters contain 5 to 9 blossoms. The plant's broadly elliptic leaves range from 2⅜" to 3⅛" in length, presenting a glossy, dark green surface. This variety maintains an upright and robust growth habit, ideal for adding structure and subtle colour contrast in mature garden settings.