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Southern Indica Azaleas (Rhododendron sp.)

• Cultivars: Formosa, George L. Taber, G.G. Gerbing
• Common Names: Azalea (preceded by cultivar name)
• Recommended Use: Feature plant in the landscape, particularly when in bloom, that can serve as the foundation for landscape arrangements. Absent blooms, these plants provide a dense screen with the evergreen foliage that maintains a moderately imposing feature in the landscape year-round.
• Exposure: Full sun to part shade, with more profuse blooms when provided more sun
• Size: 6-8 feet high, 4-6 feet wide
• Habit: Spreading, mounding habit that lends a natural woodland appearance to the landscape
• Bloom Time: A powerful floral display that lasts nearly two weeks, starting in mid-March (south Louisiana) or mid/late-March (north Louisiana). Flower color options are certainly not limited with Southern Indica azaleas. Formosa provides a vivid purple/lavender to the landscape, George L. Taber adds a soft pink touch, and G.G. Gerbing lends a bright white display that illuminates the landscape.
• Maintenance Category: Low
• Water Use: Regular watering during establishment. Reduce water once established in the landscape, but extra irrigation during the heat of summer is beneficial.
• Highlights: Showstopping blooms are sure to attract attention in the neighborhood, drawing in people and pollinators, particularly bees and hummingbirds, with an exceptional, albeit short, floral display. Beyond the robust blooms, this is a tough, reliable plant for Louisiana that can act as an evergreen screen and lend structure to the landscape.

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Shearing or hedging may diminish the natural, woodland appearance of this plant. Photo by Sara Shields

Summary

The iconic spring blooms of the Indica azaleas that we know and love in Louisiana originally hail from Japan. Since their introduction to the Southern landscape in the 19th century, generations have marveled at the profuse flower displays that mark the start of the spring season. While the vibrant blooms on these medium-sized selections are short lived, the dense evergreen foliage provides a presence that commands year-round attention in the landscape as either a focal point or as part of a mass planting.

The naturalized growth form, tolerance for shade and impressive floral display contribute toward efforts to create an understory garden, where it harmonizes well with tall pine trees or large live oaks in the landscape. In general, the floral display is greatest when provided with ample sunlight; however, even in part shade, the blooms are bountiful. Options for flower color abound with Southern Indica azaleas, providing hues of purple, pink and white to match the palates of all plant afficionados. Look for the lavender-colored Formosa varieties to provide a deep purple focal point in the landscape. Interested in a softer coloration? Look no further than the George L. Taber variety which provides a gentler pink hue that plays well with the whiter tones also found on the flower. If seeking a brighter bloom that incorporates an illuminating presence in the garden, then consider the Mrs. G.G. Gerbing azalea — an excellent addition to brighten up a shade garden. Consider combinations of these selections to achieve a varied floral display in springtime.

These selections have been standout specimens in the Louisiana landscape, noted for their vigor even in our hot Gulf Coast conditions. Maintenance is moderately low, where yearly pruning is not even necessary; however, when electing to prune these selections, make sure that the time is right. These selections bloom on old wood, meaning that the beautiful blooms we witness in springtime are in fact formed from the preceding season’s growth. Therefore, the best time to prune is after flower blooms begin to fade. This allows almost a full season of growth to form the flowers for the following spring. Pruning should be performed judiciously, removing unappealing and unruly branches individually, rather than shearing entirely. While shearing may not necessarily be bad, it can diminish the natural growth habit that contributes to the interest of this species when blooms are absent. Do not prune this plant before it blooms, lest you remove the floral display that you — and your neighbors — enjoy.

Indeed, azaleas prefer soils on the acidic side; however, these selections have demonstrated tolerance to a wider array of soil pH conditions, performing well even in soils that are closer to neutral. Soil pH can be lowered at a grander scale by amending soils with elemental sulfur; however, the addition of organic mulches can help maintain a proper pH in the landscape with less effort, provided initial conditions are suitable. Soils should be well-drained, as azaleas do not appreciate consistently saturated soils. This shallow-rooted species may need more irrigation attention at installation, but water needs are not as pronounced after establishment. Fertilizer should be applied before blooms emerge (i.e., late winter, or early spring) as part of continuing maintenance. To summarize, remember to fertilize before blooms and prune right after blooms. Proper care and maintenance of these Southern Indica selections can help ensure that these plants reach their potential, providing interest for many years with these long-lived specimens, which are known to survive several decades.

While we know and love our Southern Indica azaleas, these sun and shade-tolerant historic hallmarks of the Louisiana landscape deserve their moment in the sun. With showstopping blooms for two weeks of the year — and evergreen foliage adding interest for the other 50 — these plant selections are tried-and-true performers in our landscape and present a foundational feature of the garden. Rather than picking just one, all three of these varieties are Super Plant selections for 2025.

For more information on Southern Indica azaleas and other Louisiana Super Plants, contact your local LSU AgCenter Extension office or visit LSUAgCenter.com/SuperPlants.