Live in the South? Love azaleas? Want to enjoy blooming azaleas for eight consecutive months rather than for just a few weeks in the spring? You can do that by growing a combination of native azaleas and the evergreen types. But first, it helps to know a little bit about the different kinds of azaleas.
Evergreen azaleas are viewed as one of the most iconic spring-blooming Southern shrubs. It may come as a surprise, but these common plants that put on such a spectacular show aren't from the South — they come from Asia. About 20 years ago, a new type of azalea also became commercially available, one that was not entirely welcomed by traditional gardeners who appreciated the azalea's role in declaring the start of spring. Encore azaleas are an evergreen type that blooms in the spring, but also in the late summer or fall.
Meanwhile, lurking in the background virtually unnoticed, are native American azaleas, which accomplish the same feat naturally. These azaleas — almost all of which are native to the Southeastern U.S. — have a bloom time ranging from spring to fall.
By growing a combination of the evergreens, including the Encores, and native azaleas, it's possible to have one or more azaleas in flower from March to October, or longer if you live in the Deep South.
Extending the bloom time in gardens beyond the always-anticipated spring flush, however, will require perseverance and a bit of geographic luck. You will need perseverance because mainline retail nurseries typically do not stock native American azaleas. You'll most likely find them at specialty nurseries, local plant club sales, local azalea club sales or though an online search. That, of course, requires more work than driving to the nearest garden center or box store. You'll need some geographic luck, too, because you'll need to live in an area with a prolonged growing season — think the Southeastern Piedmont and the Deep South. Even though some azaleas are native to the cooler climates of higher elevations in the Appalachian Mountains and native azaleas can be grown in Northern gardens, the growing seasons in those areas are too short to bloom azaleas into the short days and cool nights of fall.
If you're lucky enough to live where you have an early spring and moderate temperatures that linger into October — or even November and possibly December in the Deep South — here’s a guide to understanding why evergreen azaleas are more readily available than natives, where to buy the natives and how to combine the different types to have azaleas continuously in bloom from spring to fall or even the holidays. It's based on advice from Carol Robacker, a researcher in the breeding and genetics of landscape plants at the University of Georgia, Griffin Campus and a bloom calendar for native azaleas on the website of the Azalea Society of America.
Evergreen vs. native azaleas
Encore azaleas, like the Autumn Rogue, are popular among home gardeners for their hardiness and their extra blooms late in the growing season. (Photo: Encore Azalea)
Evergreen varieties are readily available because wholesalers can quickly and easily propagate and raise them to a saleable size, and they are inexpensive for homeowners to buy and easy for them to grow. Even more importantly from the homeowner's perspective, they make excellent foundation plants since they stay relatively small, and they don't lose their leaves in winter.
The Encore types extend the azalea sale season for retailers and give homeowners an extra bang for their buck because the plants produce an "encore" of sporadic blooms in the summer and flower heavily in the fall. An added benefit of the Encore varieties is that the 29 varieties of Encore azaleas have exhibited a higher resistance to insect pests than traditional azaleas, can be grown in full sun (whereas most of the evergreen types prefer more shaded conditions) and, based on university trials, are cold hardy into the Midwest and Northeast.
It's a different story with the 17 species of native azaleas, 15 of which grow in the Southeast. They have not enjoyed the same interest as evergreens in either the nursery trade or among homeowners. That's because they are different from the evergreens in several key ways. Natives are more difficult for wholesalers to root than the Asian varieties, are slower to grow into a salable size and therefore cost more than evergreens at retail outlets that might carry them, can sometimes be a challenge for homeowners to get established, are all deciduous and tend to grow into large shrubs or small trees. The last two characteristics mean they aren't foundation plants, which has limited their popularity with homeowners and, thus, the nursery trade.
On the positive side for native azaleas, they produce a wider range of colors, most notably yellow and orange, than the pink, white and red flowers of the Asian types. "There's an attempt to get these colors into the evergreen azaleas, but we haven't seen that yet," said Robacker. "Whoever gets a yellow evergreen azalea would sell a bunch of them."
You might be wondering why the nursery trade has not bred evergreens and natives. Actually, some have tried, Robacker said, particularly in an attempt to get a yellow flower. "The deciduous U.S. natives just don't cross well to the evergreens," Robacker said. "They may all be Rhododendrons, but they are just too divergent." The Southeastern natives do cross well among themselves, though. In fact, Robacker said, where species ranges overlap its more common to find a natural hybrid in the wild than a straight species.
If you're ready to take the "azalea challenge," here's a calendar for for growing evergreen and native azaleas to enjoy their blooms from spring to fall, or possibly even later.
Spring-blooming azaleas (March-April)
If you start with the evergreens, then you will want to supplement with one or more of the spring-blooming natives, which include:
- Hoary azalea (R. canescens) – Pink to white and one of the most readily available U natives.
- Florida Azalea (R. austrinum) – Yellow to orange, fragrant.
- Pinkshell azalea (R. vaseyi) – Pink to white.
- Oconee Azalea (R. flammeum) – Orange to red. Flowers can last into May.
- Alabama Azalea (R. alabamense) – White. Flowers can last into May.
- Coast Azalea (R. atlanticum) – White to pink. Flowers can last into May.
- Pinxterflower (R. periclymenoides) – Pink to white. Flowers can last into May.
Late spring- to early summer-blooming azaleas (May-June)
To maximize your chance of blooming azaleas into the late spring and early summer, you'll have to add some of the U.S. natives to your garden.
The natives that bloom in late spring-early summer are:
- May White Azalea (R. eastmanii) – White with yellow blotch. Fragrant.
- Red Hills Azalea (R. colemanii) – White or pink but on rare occasions may be yellow or have a yellow blotch. Fragrant.
- Roseshell Azalea (R. prinophyllum) – This azalea is native to high altitudes and difficult to grow elsewhere.
- Swamp Azalea (R. viscosum; also known as R. serrulatum) – White. Fragrant.
- Flame Azalea (R. calendulaceum) – Most often orange to red but with yellow-blooming forms.
- Cumberland Azalea (R. cumberlandense) – Orange-red. Blooms into July but is a cool grower. It may not flower in the South in low elevations.
- Sweet Azalea (R. arborescens) – White. Fragrant. Flowers can last into August.
- Plumleaf Azalea (R. prunifolium) – Red to orange. Blooms as early as late June. The flowers can last into September.
The biggest problem you might run into, said Robacker, is during the latter end of the period as the summer heat starts setting in. There can be a gap, she said, between the time the late spring bloomers finish and the summer-blooming Plumleaf Aalea (R. prunifolium) comes into flower beginning in late June. Some breeders have attempted to fill in this gap by breeding early and late-blooming natives. Look for these crosses among that group:
- R. prunifolium x R. canescens — blooms late May thru June
- R. serrulatum x R. canescens — blooms late May to early June
- R. flammeum x R. prunifolium — blooms late May to late June
Summer- and fall-blooming azaleas (July-October)
"Encore azaleas are also very useful in filling the summer bloom gap as many will follow their spring bloom with sporadic bursts of blooms starting in July and building to their heavy fall bloom," said Keith Winger, sales manager at Tom Dodd Nurseries in Semmes, Alabama. "Fall most definitely is their heaviest flowering time," he added. "They will continue to bloom until it turns real cold. A few frosts don't set them back much." In Semmes, for instance, Winger said Encore varieties such as Amethyst and Sundance ( will even bloom into December if temperatures remain mild.
A spring-blooming U.S. native, "Windsor Buttercup," can also re-bloom in the fall Robacker said. Unfortunately, this results in fewer blooms on the plants in the spring. In addition to R. prunifolium, the last of the natives to begin flowering in summer with blooms that can last into fall is:
- Hammock Sweet Azalea (Rhododendron viscosum var. serrulatum) – A late-blooming form of R. viscosum, which is a variable species. White. Fragrant.
Combining natives azaleas and history
The 'Admiral Semmes' azaleas will produce a number of honey suckling-looking flowers. (Photo: Dodd & Dodd Nurseries)
If you enjoy Southern history, you can combine that interest and a love of azaleas through the "Confederate Series," a group of spring-blooming natives with large flowers named after some of the most well-known men who fought for the South in the Civil War. True to their namesake, these azaleas thrive in the South's summer heat and humidity. All should be planted in semi-shade where there is good drainage. The group includes 11 cultivars. Here are five of the best known:
- Admiral Semmes. The mildew-resistant plants form a 5 x 5-foot shrub and produce many clusters of large and extremely fragrant, honeysuckle-like, yellow flowers. Raphael Semmes is best known as the captain of the CSS Semmes, the most famous of the Confederate commerce raiders. He still holds the record for number of enemy ships sunk – 65.
- Nathan Bedford Forrest. The plants produce bright orange flowers. Forrest was one of the South’s most daring but polarizing commanders. After the war he was associated with the founding of the Ku Klux Klan and became its first Grand Wizard, though he later distanced himself from the group.
- J.E.B. Stuart. These plants produce pink flowers. Gen. James Ewell Brown Stuart, known as Jeb because of his initials, served under Thomas “Stonewall” Jackson. He was late arriving at the decisive Battle of Gettysburg, which is still the subject of debate and controversy among historians.
- Stonewall Jackson. This is a profuse and fragrant bloomer that produces large clusters of orange-red flowers. Thomas Jonathan "Stonewall" Jackson was the best-known Confederate commander after General Robert E. Lee.
- Robert E. Lee. This azalea produces large very bright reddish flowers. Lee was an American general who turned down an offer of senior command in the Union Army when Virginia seceded from the Union. He became commander of the Army of Northern Virginia.
How to grow native azaleas
Pinkshell azaleas are a spring-blooming native variety. While natives take a little extra work to establish, they're easy to maintain after that. (Photo: Col Ford and Natasha de Vere/Wikimedia Commons)
"Site selection is really important," Robacker said. "These are not foundation plants," she added. "They're more understory in the landscape." That means they prefer the semi-shade of dappled light that filters through the canopy of nearby taller deciduous trees.
You can grow them in full sun if that's your only option or the best one for your landscape. But that will change their architecture. "They will bloom way heavier and get much thicker than their often more natural open shape when grown under taller trees," she said. But that will present another issue. "You will have to water them like crazy," she advised. Conversely, she added, don't put them in too much shade or they won't get enough sunlight to bloom.
When you take them out the pot, plant them a little high, which means the soil level from the pot should be a little above the level of the ground where you are planting them. "Whatever you do, don't plant them so that the pot soil level is below the ground soil level. Mulch them because you will want to keep the soil around them moist. Water them well for the first couple of years."
While the natives may be more challenging to establish than evergreens, once established you can almost ignore them, Robacker said. At that point, they are actually easy to grow, they are just slow growing. The most they really seem to need, she said, is for you to water them during droughts. Also be sure you don’t put lime on them, Robacker said. Lime "sweetens" the soil, and azaleas prefer an acidic soil.
Native azaleas are prized not only for their flowers but their natural shape and don’t need much pruning. About the only time they need pruning is if they are stretching out of the area where you planted them and their branches are starting to become a problem. Even then she said, they likely will only need a light pruning. But, she stressed, do that after they have flowered and before they have formed flower buds for next year. Native azaleas form their buds on old wood, she added. Also in the "whatever-you-do" category, don't prune them into a round shrub. "Please don't make meatballs out of them," she said.
Where to find azaleas
"This is another reason people don't have (native azaleas) in their gardens," said Robacker. "[The plant nurseries] just don’t have them." For a list of nurseries that sell native azaleas, visit the Azalea Society of America's website. Also inquire about availability at area specialty nurseries and plant sales at local community gardens, native plant societies, azalea clubs and botanical gardens.