Rhododendron austrinum
Common Name: Florida azalea 
Type: Deciduous shrub
Family: Ericaceae
Native Range: Georgia and Florida
Zone: 6 to 9
Height: 6.00 to 10.00 feet
Spread: 4.00 to 6.00 feet
Bloom Time: April
Bloom Description: Yellow, peach, orange-red
Sun: Part shade
Water: Medium
Maintenance: Medium
Suggested Use: Hedge
Flower: Showy, Fragrant
Attracts: Hummingbirds, Butterflies
Tolerate: Rabbit

Culture

Best grown in acidic, light, sandy, well-drained soils in part shade. Tolerates well-drained humusy loams. Prefers a sun dappled shade or high open part shade. Foliage may scorch in full sun. Acidify soils prior to planting and thereafter as needed. This shrub is not reliably winter hardy to the St. Louis area where it should be planted in a location protected from strong winter winds. Shallow, fibrous root systems (do not cultivate around shrubs).will benefit from a good mulch (wood chips, bark or pine needles) for retention of moisture, stabilization of soil temperatures and winter protection. Consistent moisture is best, but soils must drain well (doesn’t like “wet feet”). Poor drainage inevitably leads to root rot, therefore raised beds/plantings should be considered in heavy clay soils such as those present in much of the St. Louis area. Roots must never be allowed to dry out. Clip off spent flower clusters immediately after bloom as practicable. Slowly naturalizes by root suckers.

Noteworthy Characteristics

Rhododendron austrinum, commonly called Florida azalea or Florida flame azalea, is an upright, deciduous shrub that typically grows to 6-10’ tall with loose, irregular branching. It is native from northern Florida and southern Georgia west to southern Alabama and Mississippi where it is most often found in moist woods and along streams. Fragrant, funnel-shaped flowers in dense clusters (8-15 flowers per cluster) bloom in early spring just before or as the foliage emerges. Flowers range in color from yellow to peach to orange-red. Each flower is about 3/4” long, but stamens protrude well beyond the corolla in an upward arc to 2” long. Elliptic to obovate, dull green leaves (to 4” long) are softly pubescent. Flowers give way to woody capsules (to 1” long).

Genus name comes from the Greek words rhodo meaning rose and dendron meaning tree. Transferred from the Greek name for Nerium oleander.

Specific epithet means southern.

Problems

Azaleas are susceptible to many insect and disease problems, including but not limited to canker, crown rot, root rot, leaf spot, rust, powdery mildew, aphids, borers, lacebugs, leafhoppers, mealybugs, mites, nematodes, scale, thrips and whitefly. A healthy plant in the proper environment with proper care should have limited problems, however.

Uses

Group or specimen for shrub borders, mixed borders, open woodland gardens, native plant gardens and open shade gardens. Effective near patios and as a specimen around the home.