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Charming Native Azaleas Entice Gardeners Into Spring Love Affair
Varieties and colors, from subdued to brilliant, abound in our region, writes Rick J. Lewandowski, Director of the Mt. Cuba Center in Delaware.
by Rick Lewandowski - 5/12/2008
I think it’s fair to say that American gardeners have a love affair with spring flowering shrubs, particularly azaleas and rhododendrons.
From late April through late May each year, gardens throughout our region are ablaze with flowers borne on bold, leathery evergreen rhododendrons and small-leaved, finely textured, dense evergreen azaleas. Flowers come in a myriad of colors from the purest whites and subdued mauves to the most outrageous day-glow pinks, oranges, and reds.
There is little doubt that azaleas and rhododendrons are among our most favored garden shrubs. Yet, few gardeners realize that there are several under-appreciated deciduous azaleas native to the eastern U.S. that possess adaptability, beauty, floral fragrance, and multi-seasonal interest. These qualities make them outstanding garden candidates just waiting in the wings for wider use.
Expanding Your Options
Novice gardeners can hardly be blamed for not knowing this fact, in part because there are quite literally thousands of exotic azalea and rhododendron hybrids that have been selected and marketed over the years. As with roses, each year new selections of azaleas and rhododendrons appear to satisfy the insatiable desire of the gardening public for the “new and unusual.”
Furthermore, unless you’ve stumbled across hillsides during the spring, richly layered masses of native azaleas blooming in an array of bright colors, or visited public gardens that showcase the enormous variety of native azaleas, you’d hardly suspect that these plants exist, let alone realize that they could be the perfect choice for your garden.
Well, folks, that’s about to change!
Diversity at Our Fingertips
Nature has provided us with no less than fifteen species of azaleas that grow naturally in the forests of the eastern United States. They thrive in conditions ranging from sun to shade and wet to dry. Most of these species, selections, and hybrids, natural and man-made, are excellent candidates for gardens in our region.
Depending upon the species, native azaleas can produce flowers as early as late April to as late as the end of August, ranging in colors from white, pink and yellow to brilliant orange and bright red. Additionally, several native azalea species produce colorful foliage displays in autumn as they prepare to shed their leaves.
Making Wise Choices
Native azaleas, like all azaleas and rhododendrons, belong to the heath family (Ericaceae). One of the important traits of this family is that virtually all its members require acid soil conditions to grow properly. Though native azaleas are generally adaptable garden shrubs, they do need a soil pH below 6.5 for best growth and flowering.
The lesson to take away is that if your soils are alkaline (a pH above 7), you should avoid planting native azaleas, because they will struggle and perform poorly in your garden. Remember the mantra: good gardens are designed around plants that perform best under yourgardening conditions.
Native Azalea Primer
However, if you have the right garden conditions, there are several native azaleas to consider. Hopefully, you’ll become as enthralled with native azaleas as I am and find room in your garden to add one or more species for diversity and pleasure. Here’s a short list of a few favorites:
Pinkshell azalea (Rhododendron vaseyi) is a star in the early spring garden, flowering by the last week in April (pictured top right). It produces stunning soft pink funnel-shaped flowers on leafless, coarsely-branched upright plants reaching 5 to 8 feet tall. Pinkshell azaleas thrive in part shade or along woodland edges in well drained, seasonally dry soils. As an added bonus, pinkshell azaleas produce stunning bronze to red foliage displays in autumn.
Pinxterbloom azalea (Rhododendron periclymenoides) is the native azalea commonly found in woodlands throughout our region, producing clusters of delicate pale to bright pink narrow tubular flowers in early to mid-May (pictured second from top). Pinxterbloom azalea generally grows 4 to 6 feet tall in the garden and is especially tolerant of dry, sterile soils once it is established. It, too, can develop excellent fall color ranging from yellow to bright red.
Alabama azalea (Rhododendron alabamense) provides a stunning display in mid-May with large clusters of white, funnel-shaped flowers, each marked with a yellow blotch (pictured third from top). Adding to this feature, the flowers have a very pleasant scent. Alabama azalea becomes an upright irregular shrub 6 to 8 feet tall and is quite heat tolerant. It is capable of withstanding more sun than most native azaleas and often produces yellow, purple, or reddish fall foliage displays.
Florida azalea (Rhododendron austrinum), though native only in the deep South, is a very adaptable azalea that produces brilliant yellow to yellowish-orange, heavily scented honeysuckle-shaped flowers in large clusters from early to mid-May (pictured third from bottom). There are few plants that can compete with the intoxicating aroma of its flowers. Florida azalea can grow to 10 feet tall and is an excellent shrub for the back of the border.
Coast azalea (Rhododendron atlanticum) is another of our native azaleas found primarily – you guessed it – along the coastal areas of Delaware and the surrounding region (pictured second from bottom). Coast azalea has stunning grayish-green foliage on an upright irregular shrub 3 to 5 feet tall. It produces white, funnel-shaped, highly fragrant flowers, occasionally tinged with pink, in small clusters during mid-May. Coast azalea spreads slowly by root suckers that emerge around its base, making it an excellent shrub for massing. It also tolerates sun better than most native azaleas.
Flame azalea (Rhododendron calendulaceum) is among the most beloved native azaleas for the shady garden or woodland garden. In mid to late May, flame azalea produces fiery clusters of brilliant yellow to radiant orange, funnel-shaped flowers in loose clusters (pictured bottom right). Often the flowers are so bright that they light up the shady woodland garden. Flame azalea is a loosely branched shrub that can become 5 to 8 feet tall, preferring moist, organic, and well-drained soils. Though its flowers are less dense overall, their effect is magical.
Enhance Your Garden
Of course, we’ve only scratched the surface when it comes to native azaleas. This short list is just a glimpse of the diversity and charm awaiting inquisitive gardeners. Plant breeders and nurseries have done much work over the past several years to create and select superior forms of native azaleas to further expand your choices.
So, now it’s your turn. Will you get out there and explore the world of native azaleas to enhance your garden this spring?
If you do, you’ll almost certainly discover a native azalea worthy of a place in your garden.
And, please remember, I told you so! Happy gardening.
(This gardening column by Rick J. Lewandowski originally appeared in the Wilmington News-Journal newspaper.)