The best azaleas to grow in shade are those with evergreen leaves. They grow well in light or filtered shade cast by large deciduous trees. A site with morning sun and afternoon shade is also ideal. Plant azaleas next to a building or wall, near larger shrubs, or on a slope for protection against dry winds.
Most evergreen azaleas are native to Japan, although some originated in China, Korea and Taiwan. Dr. Fred Galle identified more than 70 groups of evergreen hybrids in his book, Azaleas.
Southern Indian Azaleas
The most common azaleas in Southern gardens are Southern Indian Azaleas, which are also called Southern Indica Azaleas. They are fast growing shrubs that need plenty of room to grow – up to 8 feet tall and 10 feet wide. They can be pruned to a smaller size each year after flowering. They are not reliable in extremely cold areas.
Southern Indian Azaleas have large flowers in early spring in shades of purple, pink, rose and white. Some popular varieties are ‘Formosa,’ with deep purplish magenta blooms; and ‘Elegans’ with pink blooms.
Kurume Azaleas are compact shrubs with dense foliage. They grow 2 to 6 feet tall, and 2 to 5 feet wide. They grow slowly to moderately and are cold tolerant.
Many small blooms appear in early spring, often hiding the foliage. The flowers are shades of pink, red, salmon, reddish orange, violet, purple and white, as well as bi-colors. Pink ‘Appleblossom’, salmon ‘Coral Bells’, and white ‘Snow’ are some reliable varieties of Kurume Azaleas.
Kaempferi Azaleas have an upright form that grows 4 to 10 feet tall, and 5 to 6 feet wide. They bloom in late spring, with flowers in shades of red, reddish-purple, reddish-orange, salmon, pink and white. The plants are extremely cold hardy. Some good varieties of Kaempferi Azaleas are the white ‘Anna Marie’, the pink ‘Cleopatra’, and the red 'Carmen'.
Satsuki Azaleas grow in low mounds 2 to 4 feet tall and wide. Showy flowers bloom in mid-summer in shades of pink, peach, purple and white. The flowers may be solid, striped, speckled or edged with a contrasting color. There are hundreds of varieties of Satsuki Azaleas. ‘Gumpo’ is a variety available with white or pink flowers, ‘Higaso’ has deep rose blooms, and ‘Eiten’ has purple blooms.