Rhododendron x ‘Klondyke’ (Exbury Hybrid) – One of the best deciduous azaleas with intense golden-orange flowers (with a red-tinged reverse) emerging from coppery-red buds in May. The highly fragrant blooms are complimented by the newly emerging bronze-green foliage, which turns mahogany red in the fall. RHS Award of Garden Merit. Grows 4-6′ high by 4′ wide. Zone 5.
Rhododendron x ‘Lemon Lights’ (Northern Lights Series) – This 1996 introduction was bred at the University of Minnesota and has the hardiness to prove it. It bears fragrant trusses of pale yellow flowers (with a darker blotch and throat) in May. The mid green foliage of this deciduous shrub shifts to maroon in autumn. Grows 5′ high by 5′ wide. Hardy to zone 4.
Rhododendron x ‘Cannon’s Double’ (Exbury Hybrid) – This RHS Award of Garden Merit winner features lightly scented double flowers of a pale apricot-pink that emerge from deep rose-pink buds in May and June. These are borne in trusses of 7 to 8 blooms. This cross of R. ‘Corneille’ and R. ‘Cecile’ also features bronze autumn tones. Grows 6′ high by 5′ wide. Hardy to zone 5.
Rhododendron x ‘Northern Hi-Lights’ (Northern Lights Series) – Another of the University of Minnesota introductions that was released in 1994 and features good hardiness. It bears stunning clusters of sweetly fragrant white blooms, with a prominent yellow blotch. This mildew resistant cultivar also has burgundy autumn tones. Grows 4-7′ high by 4-5′ wide. Zone 4.
Rhododendron x ‘Golden Eagle’ (Knaphill Hybrid) – An older deciduous azalea cultivar bred by Waterer using Rhododendron calendulaceum. It features bright reddish-orange blooms (3″ wide with a prominent golden-yellow bar) borne in large trusses of 10-12 flowers. The glossy green foliage turns a bronze-red in fall. Grows 4-7′ high by 4-6′ wide. Hardy to zone 5.