Star Gardener: The Broad Range of Native Azaleas

Rhododendron viscosum
The Marydel coastal azalea, above, blooms in early June, as does the unknown fragrant azalea, below. Abby Jane Brody Photos

If you’ve ever biked or run on Old Stone Highway or other roads near the bays and harbors in late June or early July, you could hardly miss the spicy fragrance of a white-flowered shrub on the edge of the woods. 

It is the swamp azalea (Rhododendron viscosum), and it does not deserve to be relegated only to its native habitat; it grows just as well in the garden, and in any soil, not just in wet areas. (Azaleas are in the genus Rhododendron.) Like the other 14 species of azaleas that grow in the east, it is deciduous, has excellent fall color, and is attractive to beneficial insects and birds. Most do very well in shade or dappled shade, although I’ve found they can do well in sun, too.

You should definitely consider them for your garden. (Warning: They are candy for deer.)

Native azaleas come in a broad range of colors, from white and pastel pink and yellow to saturated yellow, gold, orange, and red. In addition to the species, there are many hundreds of hybrids. George Biercuk, who gardens in the woodlands in Wainscott and who has long favored deciduous azaleas, reports the color range has been broadened to violet and lavender, too. 

We both disagree with the English luminaries Gertrude Jekyll and Vita Sackville-West, who cautioned about not planting azaleas with rhododendrons. I suspect they were more familiar with the startlingly bright Ghent, Knap Hill, and Exbury hybrids that didn’t harmonize with the rhododendrons that were popular in England at the time.

Many native azaleas and their hybrids do work well with rhododendrons. There are selections that flower sequentially from April before the leaves unfurl until September, times when there is no competition from rhododendrons.  

One of the first to open in my garden is the pinkshell azalea, R. vaseyi, and it is entrancing. Soft bi-colored pink flowers open before the leaves and remind me of a flock of fluttering butterflies. A multi-stemmed bush, it is about seven or eight feet tall after about 25 years. Unlike the more familiar and popular evergreen azaleas that are blocks of often strident color, the pinkshell azalea lends a note of grace to the garden just as it is awakening in late April/early May. 

In flower now, and there is a bush at the Mimi Meehan Native Plant Garden, is the coastal deciduous azalea R. atlanticum and its hybrids. The late great plantswoman Polly Hill, whose garden on Martha’s Vineyard has been turned into an arboretum open to the public, introduced a number of atlanticum plants and natural hybrids from a swarm that she found near the Choptank River on the Maryland-Delaware border. They have a pleasant fragrance, and the flowers range from white tinged with pink to pink. I am growing Marydel, with full clusters of flowers. The buds are a deep pink, and because they open sequentially they are combined with white flowers flushed with pink. It is flowering profusely in deep shade, although the plant at the native plant garden receives a fair amount of sun.

Mr. Biercuk selects his azaleas on the basis of fragrance: “It grounds us and lifts the spirits.” If there is one with striking color that captures his fancy, he’s willing to forgo the fragrance.

My criteria, on the other hand, are color and timing. About five years ago I naively thought that adding more shrubs to the native plant garden would reduce maintenance. The shady areas lacked color during July and August when the garden has the most visitors, so I sought out native azaleas flowering then. 

Ernest Koone of Lazy K Nursery in Georgia, a specialist in native azaleas, was infinitely patient, and we finally selected R. Millennium, a saturated red hybrid that has lovely bluish foliage and flowers in July, planted along the wall of the East Hampton Star building, and the plumleaf rhododendron, R. prunifolium, in shades of pinkish orange to bright red in August, at the rear of the garden.

I can’t say the need to weed has been reduced yet, but the shady parts of the garden have begun to vie with the colorful sunny area in midsummer.

Another successful summer-flowering azalea in my own garden is the hybrid Pennsylvania. It opens in late July and early August in a rich light pink.

Whether your taste runs to vivid saturated colors or more tranquil hues, there are native azaleas and their hybrids to suit all tastes, and they deserve a place in your garden. They will be sure to please you, as well as pollinators and bees.

A late bloomer, the Plumleaf azalea, hits its peak in August.