JARS v56n2 - Landscaping with Native Azaleas: Composing a Southeastern Garden

Landscaping with Native Azaleas: Composing a Southeastern Garden
Robert B. Greenleaf
Auburn, Alabama

Coming from a family where my mother was a trained botanist and my father a plant breeder and geneticist, I suspect that my love for plants is to some extent inherited. Over a period of twenty-five years, this love and appreciation for plants has been directed towards the establishment of a garden whose foundation is the genus Rhododendron . Within that genus, the majority of the plants I grow are azaleas native to the southeastern United States. Here in east central Alabama, few plants can match the variety, beauty, and heartiness of our native azaleas. My goal was to grow and display these fabulous plants in a manner that would be aesthetically pleasing to me. Because I am a composer by profession and create large musical works which have an over-arching structure, I wanted to create an interesting and delightful structure for my garden. However, before I begin the description of this structure, I should give some background and some of the criteria for my approach to the garden and its design.

I live in the middle of an acre lot which is covered in trees, mainly pines, under which native azaleas thrive. My basic principle was to work with the location, not against it, and in general to grow mainly native plants that would be adapted to the shade and this continental climate with its extremes of heat, humidity, cold, drought, and flood, as well as to the heavy acid clay soil of the Alabama piedmont. Even before we built our house, my wife and I procured some native azaleas from S. D. Coleman of Fort Gaines, Georgia, and planted them on our acre. These included a number of Rhododendron canescens and R. austrinum , and one remarkable R. flammeum . Some of these stayed where they had been planted while others were moved to conform to the eventual design of the garden.

A few years after we moved into our new home, the Chattahoochee Chapter of the ARS was formed and I became a founding member. About the same time my wife urged me to clear the underbrush from the lot and landscape it, and my latent gardening desires blossomed. I visited many gardens in my area to see which plants could be grown here successfully and to decide which plants I wanted to grow on my acre. These gardens included those of Dr. R. D. Rouse, Dr. Tom Corley and Dr. R. O. Smitherman. Dr. Smitherman, a catfish breeder and native azalea lover had embarked on an extensive deciduous azalea breeding program, and Dr. Rouse, Dr. Corley, and I ended up growing out a number of his seedlings. I found my original "native only" plant tastes broadening as I was seduced by the many fabulous deciduous hybrids created through this program. Further, I became inspired to make a number of crosses myself, including crosses within a given species such as R. flammeum to procure the quantity and types of plants I needed for the design. (I must admit to a certain amount of collecting mania as well.) The generosity of these men, as well as that of many other plant lovers and nurserymen and women, allowed me to find the germ plasm needed for my planned garden.

Before the design could begin, it was important to note plant habit, size at maturity, color, bloom-time, texture, and favored microclimate in order to combine these plants into a relatively unified structure. Besides native azaleas, I was collecting traditional elepidote rhododendrons, usually those with Rhododendron catawbiense in their parentage, Kalmia latifolia , including the unusual northern cultivars, flowering trees, some evergreen azaleas, and herbaceous perennials, again, mainly those that were native to the southeast. This is the musical equivalent of determining that you are going to write tonal music using the major/minor tonal system and then learning the harmonic, melodic, rhythmic, and other options available to you within that system. You have to establish some limits but must maintain a variety of possibilities to have richness in the design and depth in the finished work. (The music of such composers as Bach, Mozart, Beethoven, and Brahms is written using the major/minor tonal system.)

As I acquired plants through propagation, seed, purchase, and gift, the basic design concept took shape. It was to divide the garden into rooms or areas which would be separated from each other by large evergreen plants or under-story trees. However, the possibility for different vistas needed to be considered, as well as paths that would lead the viewer by beautiful plant groupings or which, at a corner or turn, would suddenly reveal a beautiful view. Further, the issue of scale had to be factored into the design. How large was each "room" to be and what would the size of the plantings for that room be in ten years? How far apart should the plants be spaced?)

Fortunately, my lot included a number of lovely, mature native dogwoods which could for the most part be incorporated into the room concept and which helped determine room placement. Elevation changes also helped determine dividing lines. These included terraces which had been built during the 1930s, one of which created a rough loop around the house and covered about two thirds of the lot, the house effectively being in the center of a bowl.)

Within each room or area of the garden, the strategy was to plant in layers, with flowering trees presenting backdrops for evergreen rhododendron or kalmia, which in turn would be faced by deciduous azaleas which in their turn would provide a backdrop for beds containing herbaceous perennials. Variety coupled with similarity would give interest and unity to the design. (In music, this is similar to presenting themes in the exposition of a Sonata Allegro form, then developing the themes in a development section, and finally bringing them back in the recapitulation. Within the structure, the thematic material would determine the spirit or nature of the work - native azaleas in hot reds, yellows, and magentas can create high drama like the first movement of Beethoven's Symphony No. 5 or soft pinks, whites, and yellows with an occasional accent of red or magenta could give the feeling of a serene Mozart slow movement.) With the different blooming times of the season each layer could provide its own interest and different character, and visual depth could be achieved by the interaction between layers.

Partly because of the curves of the terraces and partly because there are very few straight lines in nature, I preferred to organize the plantings on curves wherever possible. Even on the edges of the lot, this could be implied by grouping plants by texture, bloom-time, and color, with one plant planted slightly more forward than two on either side, thus forming a visual group which tricks the eye into seeing a clump rather than a line. Occasionally, individual plants of contrasting color or texture would be added to a grouping to provide spice and interest.

Finally, with proper grouping by bloom times, all the quadrants of the garden would have something in bloom for about a period of a month and a half -  from the last week of March through the first week of May. Additional patches of bloom would occur into June with a few plants blooming in July and August.

R. flammeum
S. D. Coleman's selection from R. flammeum .
Photo by Robert B. Greenleaf

The first major "room" in the garden to be planted was to the left of my drive and had two curved plantings on either side of the entrance. These each began with pale yellow Rhododendron austrinum or R. austrinum x R. alabamense hybrids (some native and some created) grading by color gradually to gold as one entered the room, then continuing to pale orange R. flammeum grading gradually to deep hot red R. flammeum at the back of the room. Still on a curve, the left back "corner" then graded from red to deep magenta R. flammeum hybrids back to pale pink with an orange petal. The right "corner" was anchored by the hot orange R. flammeum selection from Coleman, grouped with hybrids derived from it, including frilled multicolored pinks and peaches and one yellow for accent and fragrance. Part of the strategy was to plant enough plants of fragrant R. austrinum near the R. flammeum for the viewer to enjoy fragrance while viewing the non-fragrant but dazzling R. flammeum . Behind the left corner was a mature dogwood and behind the right corner was a Carolina silverbell, Halesia carolina . Also providing a backdrop were R. 'Dexter's Giant Red', R. 'English Roseum', R. 'Dexter's Brandy-green', R. 'Scintillation', R. 'Tripoli'*, and Kalmia latifolia 'Ostbo Red'. Additional backdrop plantings included three different buckeyes, Alabama croton, S tyrax americana , Magnolia virginiana and needle point palm. In the center of the room, around a large pine and one dogwood, I planted a circle of azaleas alternating yellow R. austrinum with orange R. flammeum . These planting are now fully mature and the azaleas stand some 12 to 15 feet (3.5-4.5 m) tall, are nearly as wide, and are covered with thousands of blooms each year.

While the basic design was being implemented, nature was busy taking a hand in the proceedings. In 1994, Hurricane Opal came through and dumped three major pine trees on my house, with nineteen other large pines falling across my various plantings, including some 2,600 azalea seedlings in pots. This was rapidly followed by an extreme dip in temperature which killed half of the plants in pots. Trying to avoid demoralization, I managed to adjust the design to take into account the new reality of more open space. Grass was planted around the house in fairly narrow curved bands that broadened out in the backyard. This provided walking areas in front of beds and plantings around the house and also along the sweeping terrace in the backyard. I broke up the backyard lawn with two kidney shaped island beds, one full of evergreen azaleas and rhododendrons, and one containing two dogwoods with the lower limbs pruned off to allow for a vista from either end of the yard that included the main sweep of the terrace.

The evergreen kidney shaped bed provided multiple functions. First, it was full of a riot of beautiful plants, including such leggy plants as Rhododendron 'Sappho,' which could be grouped with more densely growing plants to create a solid evergreen mass. Then, it blocked the view from a path to the left side of the house, forcing the viewer to walk up the path and around the bed to catch a full view of the sweeping terrace and screened gazebo. It also provided counterpoint to the other kidney shaped bed, which was set at an oblique angle to it. Finally, a viewer turning the corner from the right side of the house would see the gazebo appear to float out of the top of the bed, and the viewer from that position would be forced to walk around the bed or follow the curve of the terrace in order to reach the gazebo.

In keeping with the master plan, the sweep of the terrace was planted in layers, the backdrop provided by native dogwoods, to which I added dogwood 'Junior Miss', Halesia carolina and Halesia carolina var. diptera . Still in back and above the terrace but in front of the trees I added a long curve of Kalmia latifolia including natives and the varieties 'Sarah', 'Bullseye', 'Nipmuck', 'Pink Charm', 'Hearts Desire', 'Olympic Fire', 'Carousel' and 'Ostbo Red'. In front of these and below the terrace I planted groupings of mid-season blooming deciduous azaleas in whites and yellows including Rhododendron alabamense x R. occidentale , R. alabamense x R. molle , R. atlanticum x R austrinum , R. 'Cannon's Double' x R. austrinum , and R. 'Chetco' x R. austrinum . Spots of stunning hot pink were added with groups of R. flammeum x R. canescens . All of this was then faced with a curved row of nineteen superb R. flammeum selected for variety in color and flower form, ranging from hot, blood reds to gaudy oranges with yellow petals and frilly rims. All of these plants tended to form ball trusses. The R. flammeum are smaller than the back plantings making for proper display. In all, on this one curve, are fifty-four deciduous azaleas. Thanks to Hurricane Opal, the more open yard gives all of these plants enough sun to make them bloom profusely. Finally, the R. flammeum are faced and interspersed with clumps of blue Phlox divericata , Iris cristata (the rare white form), Carolina lily, atamasco lily, and various trilliums, gingers, and other irises. When in bloom, it is a joy to behold.

Partial view of the curved terrace.
Partial view of the curved terrace.
Photo by Robert B. Greenleaf

There are numerous other plantings and groupings of wonderful plants throughout the yard including a group of species Rhododendron alabamense . This is one of the great plants on earth with its white blossoms with yellow petals forming ball trusses and its intense lemony fragrance. This group is planted so the prevailing southwesterly wind will waft its fragrance over the occupants of the gazebo. There are various curved beds of herbaceous perennials, including one near the entrance to the gazebo. These include some twenty-six species of trillium and many other wild flowers.

Proper culture and maintenance of the garden is essential for the garden to grow and bloom properly. Water is supplied through drip irrigation, a must during extended periods of drought. The plants all prefer the usual rhododendron mix of ground pine bark with soil in a minimum of ratio of two parts bark to one part soil, along with proper soil pH and fertility. They also need mulching which I provide with pine straw. No matter how good the planning, planting, or care, some design ideas don't work, or plants simply die or will not grow. Then flexibility is in order to find a different location or design solution, or to find a replacement plant that will work aesthetically. A garden is really a work in progress rather than a fixed form, perhaps like a set of continual improvisations on a theme. The garden varies from year to year and the blooms, like musical performances, are ephemeral. This is part of its enduring charm.

I hope some of the basic design principles I have used might prove useful in your garden. At the very least, I hope I have inspired you to try a design of your own. For me, the result is a delight to the eye and a balm to the soul. My yard provides a pleasing and peaceful place to walk whether in bloom or not. I invite you to come see my efforts and those of my friends on the Auburn/Opelika garden tour during the 2002 ARS Annual Convention in Atlanta this spring.

* Name is not registered.

Dr. Robert Greenleaf, an avid amateur gardener, is a Professor of Music at Auburn University. His compositions include the opera Under the Arbor which was distributed nationally to public television in 1994, and the orchestral piece Celebration which was toured by the National Symphony Orchestra. He will be presenting a program on native azaleas and their hybrids at the 2002 ARS Convention.