Evergreen azaleas are among the most attractive and colorful flowers we can grow in our gardens. It used to be that spring was the season for them, and they brighten our beds and planters as few other plants can. Their rich glowing colors shine out, in a wide range of tones, from pure white, through an infinite set of pink tones, into reds and purples, both light and dark. But they were always plants for spring, and for the rest of the year their green foliage is attractive, but hardly eye-catching.
In recent years there has been a revolution among these plants, with the development off varieties that rebloom later in the year, mainly in late summer and fall, bringing another season for these great plants. Currently there are two main groups of reblooming azaleas, created by two different breeders, so when it comes to adding them to your garden, lots of people are wondering which they should go with – are they the same? What differences are there? Which type should I grow? So let’s make a side-by-side comparison, figure out the differences, and see what advice to give you. . .
The Encore Azaleas
It was back in the 1980s when Robert E. Lee (his friends call him “Buddy”) began his work on the Encore azaleas. He is a keen azalea grower from Independence, Louisiana, and besides the many garden varieties, he had a lot of wild, species types as well. One of them was called Rhododendron olhamii (azaleas are part of the huge rhododendron plant group), and it came from Taiwan. He noticed that it often produced blooms during the summer months, and into fall, as well as in spring, and this got him thinking – and working. It took him a decade of hybridizing, with many different azalea varieties to create around 30 varieties, in a wide range of colors, of his Encore® Azaleas, which all have ‘Autumn’ in their name (Autumn Chiffon and Autumn Embers, for example).
The ReBLOOM Azaleas
It took Robert Head, an azalea grower from Seneca, North Carolina, 15 years to create his range of reblooming azaleas, starting a few years after Buddy Lee. He did it by creating 80,000 seedling plants from multiple crosses between promising varieties, and then selecting at first 200 and finally just 9 different plants, choosing the ones the rebloomed best, and had the best color and form. Because he had different goals, his plants have different characteristics, which is why making the right choice between them depends on thinking about your own garden.
The Same but Different. . .
The Encore and ReBLOOM azaleas have a lot in common. They are evergreen, with small leaves, forming bushes around 2 feet tall and wide. The ReBLOOM azaleas tend to be wider, up to 4 feet across, in relation to their height, which can mean you need fewer plants for mass plantings, and they tend to be neater, perhaps needing a bit less trimming than the Encore azaleas do. Both kinds, though, can be left to grow naturally, and both are fast growing, adding 8 to 12 inches of growth in a single year, under good conditions. The flowers are either ‘single’, with 5 petals making an open bowl, or ‘double’, with extra petals filling in that bowl, giving the flower a full, ruffled look. Both come in a range of colors, although obviously with over 30 Encore azaleas, and only 9 ReBLOOM varieties, there are more choices in the Encore range.
Both rebloom in the same way. Azaleas form their flower buds in clusters at the ends of the branches, developing the buds during early summer. The buds swell and grow, but they normally don’t open until a winter has passed. Rebloomers also develop their buds in early summer, which is why in both types there is a period after the spring blooming when no flowers are seen. But in these plants the buds don’t wait for spring, they begin to open as soon as they reach maturity, which is sometime over the summer. Blooming stimulates more new growth, which in turn develops buds, and these then open. This keeps going on until the cooler weather of fall tells the plants to stop, leaving a full growth of flower buds to pass through winter and be ready for the spring blooming again. This is why in both types the main reblooming is in late summer and fall, with the Encore azaleas likely to have more summer blooms than the ReBLOOM azaleas, but with a less dense fall blooming. The ReBLOOM azaleas show more distinctly two definite flushes of bloom, while the Encore type are more continuous, but with less bloom density. Of course, the individual varieties also show some variation in this, so check for that too.
Which is Best in Colder Regions?
Encore azaleas grow best in warmer zones, with zone 7 their lower limit, except for more sheltered gardens. Robert Head specifically wanted hardier plants, and the ReBLOOM varieties are all completely hardy throughout zone 6. This is great news for gardeners in zone 6, and for you, there really isn’t any choice to make – the ReBLOOM azaleas are for you. In warmer zones you can grow both types equally well, although in zone 7, if you want container plants that will be outdoors in pots all winter, then ReBLOOM would be a better choice, because it is always best to add a zone of two when deciding if plants are hardy above ground in planters.
What about Sun or Shade?
In this regard too, there are important differences. That original Taiwan azalea that Buddy Lee started with bloomed best in sun, and so do the Encore azaleas. They thrive in a lot more direct sun than most other azalea types, and they bloom best with plenty of it too. In shadier spots they will grow fine, and the spring blooming will usually be good, but they are much less inclined to rebloom well, the more shade they are in. This is great news if you have a sunny garden, or sunny beds you want lots of flowers in, and the Encore azaleas are an obvious choice for sunnier spots.
When it comes to the ReBLOOM azaleas, they do better in some shade, and while they will grow happily in full sun in zone 6, some afternoon shade, and ever light full shade, suit them better in warmer zone – and they will take some shade in zone 6 too. In a shady garden, or for shady beds in any garden, the ReBLOOM azalea varieties are going to be the top choices.
Which Will It Be?
You can see that there are real differences between the Encore and the ReBLOOM azaleas, and while both are fabulous garden plants, it pays to think carefully about where you are located, and where in your garden you want to plant them, when deciding which to go with. Of course, lots of gardeners will be able to grow both, in different light conditions, and that means you get the best of these great plants, that have revolutionized azalea growing for millions of us.