Royal azalea Rhododendron schlippenbachii Photo/Illustration: Chris Curless 1 2 3 4 5 6 7 8 9 10 11 Royal azalea (Rhododendron schlippenbachii) roe-doe-DEN-dron shlip-pen-BOK-ee-eye Genus: Rhododendron Royal azalea has large, fragrant pink blooms in spring. This large-leaved azalea also has purple-hued foliage in spring, turning velvet green in summer, and finally fading to yellow in autumn. Noteworthy Characteristics: Good fall color if grown in sun and moist soil. Care: Rhododendrons have very specific requirements, including moist, but well-drained, woodsy, acidic soil (pH 4.5 to 5.5). They must be planted shallowly, as they are surface rooted. Temperate climates with adequate rain are best, although azaleas do well in the Southeast as well. Deadhead carefully. Prefers full sun in the northern U.S. and Canada. Mulch annually with a loose material like pine needles, bark, or chopped oak leaves. Propagation: Surface-sow seed at 55° to 64°F in acidic potting mix or peat, as soon as ripe or in early spring. Garden-collected seed may not come true. Root semi-ripe cuttings in late summer of autumn. Layer in autumn. Graft in late winter or late summer. Problems: Vine weevil, whiteflies, leafhoppers, lacebugs, scale insects, caterpillars, aphids, powdery mildew, bud blast, rust, leafy gall, petal blight, Phytophthora root rot, lime-induced chlorosis. Overview Height 10 ft. to 15 ft. Spread 10 ft. to 15 ft. Growth Pace Moderate Grower Light Full Sun to Part Shade Moisture Medium Moisture Maintenance Moderate Characteristics Fragrant Flowers, Showy Flowers, Showy Foliage Bloom Time Spring Flower Color Pink Flower, White Flower Uses Beds and Borders, Specimen Plant/Focal Point, Woodland Garden Style Cottage Garden, Shade Seasonal Interest Spring Interest Type Shrubs Related Plants to Rhododendron schlippenbachii 1 2 3 4 5 6 7 8 9 10 11 Damask perpetual rose Rosa 'Rose de Rescht' 1 2 3 4 5 6 7 8 9 10 11 English shrub rose Rosa 'Fair Bianca' 1 2 3 4 5 6 7 8 9 10 11 Floribunda rose Rosa 'Betty Prior' 1 2 3 4 5 6 7 8 9 10 11 Hedgehog rose Rosa 'Frau Dagmar Hastrup' View the discussion thread.