Dwarf azaleas (Rhododendron spp. or Azalea spp.) are versatile, evergreen or deciduous shrubs. Azaleas grow in U.S. Department of Agriculture plant hardiness zones 4 through 9, and their final growing sizes vary according to the variety. Dwarf azaleas offer a range of flower colors and include the Kurume, Satsuki and Gumpo collections, general cultivars and coastal azalea (Rhododendron atlanticum).
Satsuki azaleas are compact shrubs that bear large, flat blooms 4 to 5 inches wide. "Kinpai" (Azalea "Kinpai") and "Higasa" (Azalea "Higasa") are two examples from the Satsuki range. "Kinpai" produces white-centered, reddish-orange, buff or coral flowers, and "Higasa" features deep rose-pink blooms with pale edges. Both shrubs are evergreen and grow 2 1/2 to 3 feet tall and 3 to 3 1/2 feet wide. Hardy in USDA zones 7 through 9, Satsuki azaleas are long-blooming plants that flower after the final frost dates.
Evergreen dwarf shrubs, Kurume azaleas were discovered in Japan more than 300 years ago. Since then, azalea breeders have developed many cultivars, such as "Blaauw's Pink" (Rhododendron "Blaauw's Pink"), which grows in USDA zones 6 through 9, and "Hino-crimson" (Rhododendron "Hino-crimson"), which is hardy in USDA zones 5 through 8. "Blaauw's Pink" grows 2 to 4 feet tall and wide and bears salmon-pink flowers, and "Hino-crimson" grows 2 to 4 feet tall and 3 to 5 feet wide and produces crimson-red flowers.
Gumpo azaleas are widely grown traditional dwarf shrubs that grow well in small urban gardens and in containers. "Gumpo White" (Azalea '"Gumpo White") produces white flowers with occasional red flecks, and "Gumpo Pink" (Azalea "Gumpo Pink") bears pale pink blooms. Gumpo azalea foliage is dense and evergreen, and the shrubs grow slowly into a neat, rounded, compact form 2 to 3 feet tall and wide. "Gumpo White" and "Gumpo Pink" grow in USDA zones 7 through 9 and flower in late spring.
Check the final growing dimensions on labels to find general dwarf azalea varieties at your local garden center or plant nursery. Many are available, including "Concho" (Rhododendron "Concho") and "Ginny Gee" (Rhododendron "Ginny Gee"). "Concho" grows 1 1/2 feet to 2 feet tall and wide, and bears crimson-spotted, lilac to purple blooms, and "Ginny Gee" grows 1 to 1/2 feet tall and 1 1/2 to 2 feet wide and produces white flowers with pink mottling. "Concho" is hardy in USDA zones 5 through 7 and "Ginny Gee" grows in USDA zones 6 through 8.
Coastal azalea is also called the dwarf azalea, and grows in the wild and in gardens in USDA zones 5 through 9A. The shrub grows 3 to 6 feet tall and wide and pinkish-white, fragrant flowers appear in mid-spring. Coastal azalea leaves are medium green to powdery blue green. Native to the eastern U.S. coast, this plant spreads through underground stolons, which are specialized horizontal stems. All parts of coastal azalea are highly poisonous, so don't grow this shrub where young children have easy access.