Azaleas (Rhododendron spp.) are among the most popular flowering shrubs in South Carolina, according to Clemson University. Numerous varieties of azaleas grow and bloom well in all parts of the state. Most azaleas bear funnel-shape flowers of white, pink, red, purple, salmon or orange. Spring is the most common bloom period, but some azaleas flower in summer or early fall.
Azaleas grow best in partial or filtered shade in well-drained, organic, acidic soil. They need regular deep watering and will not tolerate wet roots. A layer of mulch 2 to 3 inches deep helps keep the soil moist and cool. A fertilizer with a 3-1-2 or 3-1-3 ratio will promote growth and flowering. Azaleas should be pruned before new growth begins in spring.
Evergreen azaleas are widely used as landscape plants around homes and other buildings. Kurume and Satsuki azaleas will grow anywhere in South Carolina. Kurumes bloom in the spring, and Satsukis flower in the summer. Southern Indian azaleas are large shrubs that are not cold hardy enough for the Piedmont area. Glendale and Kaempferi azaleas are very cold hardy but do not grow well in coastal areas. Both bloom in the spring, although some varieties of Glendale flower as late as June.
Deciduous azaleas are excellent plants for woodland areas. Piedmont and Pinxterbloom azaleas are suckering plants that bloom in the spring. The blooms of Swamp azaleas are clove scented, while the foliage of Plumleaf azaleas is dark purplish-maroon. All of these grow anywhere in South Carolina. Azaleas not suited for coastal areas include Exbury and Knaphill, which bloom in the spring. Flame azaleas have no scent, but Sweet azaleas are very fragrant. Both flower in the summer.