Rhododendron austrinum is known as the Florida Azalea and blooms in early spring before as the leaves are beginning to expand. The fragrant blossoms come in shades of orange through gold and yellow, and measure approximately 2.5cm to 4cm (1″ to 1.5″) across. This species has very long stamens and the tube of the flower is often flushed with red but there is no blotch.
Florida flame azalea is well-noted for its vivid display of yellow-orange, slightly fragrant, clustered blooms appearing in spring, before the new leaves emerge. Well-suited to mass plantings in natural woodland settings, Florida flame azalea makes a traffic-stopping showing whenever it is in full bloom.
Discovered by Dr. A. W. Chapman before 1865, R. austrinum is similar in many respects to R. canescens including the sticky glandular hairs on the flower tube, but differs in the color variations which are orange to yellow rather than pink to white.
Rhododendron austrinum makes an excellent landscape plant as well as a valuable hybridizing resource, especially in southern gardens where heat tolerance is important.
This beautiful azalea has a lovely fragrance and attracts Butterflies and Hummingbirds.
You will find the Florida Azalea in abundance on many of the islands in the Azores right through to summer and in same areas early autumn.
Use and Management
Florida flame azaleas are rather straggly and upright when very young but will spread out, the large, medium green leaves causing the branches to gently cascade down to the ground. A single specimen should be allowed at least six feet of spread to develop into the cascading form. These make a dramatic effect planted in mass three to five feet apart as part of a shrub border.
Rich, moist, acid soil in light shade with some direct sun, protected from harsh winds, is an ideal location for Florida flame azaleas. Azaleas grow best in filtered shade from tall trees, but will bloom poorly when in root competition with trees. Plants are very sensitive to drought. The soil must be open and porous, yet able to retain water well. A thick mulch is recommended to help ensure adequate moisture retention and root growth. Locate the plants so that they can receive frequent irrigation. Roots are located in the top several inches, even in sandy, well-drained soil.
Pruning is seldom necessary except to control shoots that extend above the normally mounded shape. Since plants bloom on the previous year’s growth, any desired pruning should be done in spring after flowering. Pinching new shoots when they are several inches long increases branching and flower display.
The cultivar ‘My Mary’ has 2.5-inch-wide, single, fragrant yellow flowers.
Propagation is by seed sown in late fall on moist peat moss or by softwood cuttings taken in late spring.
Pests and Diseases
- Problems include iron deficiencies from too high a soil pH and mushroom root rot from overwatering or poorly drained soil.