Native azaleas for the home garden
Deciduous azaleas are lesser known than their evergreen cousins, but their beauty and variety are unsurpassed. There is a wide range of choices in size, flower color and season of bloom, and many are fragrant. Both types of azaleas belong to the rhododendron family, but evergreen azaleas are of Asian origin. Most deciduous azaleas are native to North America, with 16 species found in the United States.
Many deciduous azaleas are easy to grow in the home landscape. The wild forms are varied and beautiful, but many cultivated varieties and hybrids have also been developed that improve on the species. One very desirable trait of most all the native species is that they shed their dead flowers, unlike evergreen azaleas.
Almost all native azaleas have long, tubular flowers. This, combined with the sweet fragrance of many species, explains why people sometimes call them “bush honeysuckle.” Flower colors include white, pink, yellow, orange and red. Depending on the species, the shrubs may be low-growing, medium-sized or tall, upright or thicket-forming. Blooming season ranges from early spring to late summer. Deciduous azaleas prefer slightly acidic soils, like evergreen azaleas, but are tolerant of a wider range of soil moisture. With so many choices, almost every North Carolina gardener should be able to find native azaleas suitable for their growing conditions. Here are a few selections:
Flame azalea (Rhododendron calendulaceum) sets the mountains afire in late spring with its bright, orange-yellow flowers. A great choice for mountain gardens, it dislikes excessive heat. It may grow to 12 feet. Florida azalea (R. austrinum) is an easy-to-grow early bloomer with large, very fragrant yellow blossoms. It may grow to 15 feet. Piedmont azalea (R. canescens), the most abundant species in the Southeast, has delicately scented flowers that are white to pink. It usually has an upright shrub habit, growing to 15 feet, but it may form colonies in the right situation. Pinxter azalea (R. periclymenoides) has varying habits, from low and thicket-forming to upright (6 to 12 feet). The species usually has light pink flowers. The variety ‘Purple’ has lavender-purple blooms. Sweet azalea (R. arborescens) has white to light pink flowers with a powerful fragrance akin to heliotrope. It has distinct red pistils and filaments. This azalea likes consistently moist soil and ranges from 8 to 20 feet.
Azaleas may be planted year-round, but winter and early spring are especially good times. Mail-order sources offer the largest selection. One of the best ways to choose your favorite species is to visit a garden in bloom. The N.C. Arboretum in Asheville has a large demonstration garden that features wild species along with many cultivars and hybrids. Plan a trip in June and you can also take in the sight of thousands of blooming flame azaleas along the Blue Ridge Parkway. Azaleas by Fred Galle and Growing and Propagating Showy Native Woodland Plants by Richard Bir are excellent resources specific to our region.