Gardening in the South definitely presents certain challenges, but it is not without its rewards. Compared to the cooler climates of the North, the hot and humid weather that we garden in down south is both a blessing and a curse. Even here there are degrees of heat and humidity as Gulf Coast residents will attest, dividing the region into two separate realms of Upper South and Lower South. The best part, of course, is that we get to grow year-round, and enjoy the expanded palette of cool-season plants during winter as well as those that thrive in our summers.
Regardless of climate, the tenets of garden design apply, even if the choice of plants differs. Foliage plays a major role as combinations of texture, form, and color weave themselves into a rich, delightful tapestry. Floral panache can be used to contrast or harmonize, depending on the designer’s intentions, as herbaceous perennials and annuals and shrubs complement the surrounding foliage.
Ulimately, the most importance aspect of choosing plants for the garden is what work and what survives.
Using herbs in garden design
While garden design includes many herbs, for me their involvement is based solely on visual aesthetics and resilience. I rarely harvest for consumption except for the occasional bunch of rosemary for oven-roasted potatoes or a handful of cilantro for a Mexican dish. Culinary and medicinal herbs, along with edibles, have been in the hands of American gardeners for centuries (in particular the South) and have passed the test of time. Ultimately, the most important aspect of choosing plants for the garden is what works and what survives.
In my USDA Zone 8 garden in south-central Texas, I plant for both the summer and winter seasons, although some herbs maintain a year-round presence. Subshrubs such as culinary sage, oregano, rue, lavender, and thyme are among these permanent players. With the exception of the rosemary, however, these plants are best used only in gardens with excellent drainage and some distance from the Gulf since they are prone to summer rot in torrid climates. Rosmarinus officinalis ‘Arp’ is particularly cold hardy and succeeds where others may fail. Year-round herbs can set a softer garden mood. In summer, sage, lavender, and rosemary contribute varied greens and grays; in winter, they form a soft, silvery backdrop to the rest of the garden.
I welcome a break from monotonous green. The yellow-variegated rosemary ‘Golden Rain’ contrasts brightly with purple-leaved sage and the chartreuse leaves of golden oregano (Origanum vulgare ‘Aureum’). These and the silvery-leaved lavender and lavender cotton make excellent foils to showcase flowers in any season. As these herbs thrive in lean gritty soil, drought-tolerant summer annuals like white, pink, or lavender Madagascar periwinkle (Catharanthus roseus) and similarly colored globe amaranth (Gomphrena globosa) help brighten the scene. During the cool season, the same role can be played by such annuals as toadflax (Linaria maroccana), bachelor’s-buttons (Centaurea cyanus), stocks (Matthiola incana), and soft-colored phlox (Phlox drummondii).
In the Lower South, where oregano fails, there are similar-smelling substitutes for those who enjoy cooking. Cuban oregano (Plectranthus amboinicus) is a frost-tender, sprawling herb with 2-inch rounded, thick, juicy, leaves that are great for cooking. The variegated form has creamy white margins on light green leaves that make a cool-looking addition to pots and beds, surviving the worst heat and humidity with delicious aplomb. Also suitable for the sultry Gulf Coast is Mexican oregano (Poliomintha longiflora), a subshrub with small, oval pungent leaves and an abundance of long-tubed lavender-pink flowers during summer months.
For gardeners in torrid parts of the South, Mexican mint marigold (Tagetes lucida) makes a beautiful substitute for tarragon, which prefers to grow farther north. In late fall, the 21/2-foot-tall clumping plants are topped by golden yellow single marigold flowers that bloom in concert with the purple spikes of Mexican bush sage (Salvia leucantha) and dazzling vermilion blooms of pineapple sage (S. elegans). During winter, the rather large space left open by the dormant herbs can be filled with the bold, showy foliage of cold-hardy cabbage, kale, or mustard, along with the lacy leaves of parsley or cilantro.
For those with more tropical leanings, nothing beats the lush foliage that is easily produced during long, hot and humid summers. The large, 2- to 4-foot-tall arrowhead leaves of taro, or elephant’s-ear (Colocasia esculenta), are almost a cliché in the South, but golden- and black-leaved cultivars have given them a refreshing new look. They prefer light shade and moisture-retentive soil, as does the true culinary ginger (Zingiber officinale), whose erect stems and ladderlike leaves lend dramatic architecture to gardens in the Lower South. Add the tall stalks of the anxiety-relieving herb kava-kava (Piper methysticum), or root beer leaf, luxuriantly clad in 8-inch, heart-shaped foliage, and you have a splendid combination of shapes for the exotic-looking garden.
Colorful hot-weather foliage herbs include bronze-leaved beefsteak plant (Perilla frutescens), dark basil cultivars such as ‘Red Rubin’, ‘Purple Ruffles’, and ‘Dark Opal’, and sweet potato vine (Ipomoea batatas). The latter is now found in three fabulous colors, all of which thrive in the hottest summers. The dark-leaved trailing form, ‘Blackie’, now has a robust chartreuse cousin named ‘Margarita’, that can carpet large areas of ground if left to its own devices. Anything that grows taller than 12 inches, however, will rise above the fray. The pink-cream-and-green leaved sweet potato cultivar ‘Tricolor’ is dainty by comparison but nonetheless grows profusely through the hot weather, vining amid other plants with gentle persistence.
Where these heat-loving plants leave large openings after frost, cool-season crops can fill the void during winter months. Artichoke (Cynara scolymus) and its big brother, cardoon (C. cardunculus), may persist for more than a season in some climates but usually pass out during our nasty summers, so I use them as annuals. Their big, silvery cut leaves are exceptionally dramatic and make lovely foils for pastel shades of winter annual flowers like larkspur, stock, snapdragons, or poppies.
Clary sage (Salvia sclarea) and silver sage (S. argentea) are also shy about persisting year round in Gulf Coast climates but nevertheless make dandy specimens for the winter garden. Their broad rosettes of large olive or silver leaves pleasantly punctuate the garden for at least half of the year, especially when surrounded by violas, sweet alyssum, and miniature daisies like chrysanthemums and brachycome. Likewise the common mullein (Verbascum thapsus) and its silvery cousin V. bombyciferum add valuable bass notes to the melody of the cool season gardens.
Alliums for beauty
Some of my favorite sources for defined linear texture in the garden are also choice for the kitchen. While I never harvest the bulbs, I love to grow garlic for its subtle presence amid a variety of companions, and its dancing bloom stalks in early summer are delightful to watch. Many old homesteads here in south-central Texas are still graced by the lush straplike foliage produced by indestructible clumps of garlic leeks that have survived decades of neglect and thrive in the tended garden.
Mops of flattened, grassy leaves are the hallmark of garlic chives, which persist through all but the coldest winter freeze. Late summer finds a lavish display of glistening white flowers, densely clustered in 3-inch spheres on foot-tall stalks. While these robust little plants seem to be quite prolific in all parts of the South, seeding themselves about with abandon, I have yet to see too many in my garden as the flowers and foliage mix well with everything.
In areas with mild winters, gardeners can design with the sturdy but thrifty clumps of society garlic (Tulbaghia violacea). Its bright lavender trumpetlike stars crowd together on stems rising high above dark green leaves from late spring into summer, making this a beautiful plant in bloom. The variegated form, ‘Silver Lace’, is a jewel but blooms less and isn’t as cold hardy as the species.
Texture and color
Lacy and fern-like leaves, delightful counterpoints to bold and linear foliage, add sublime elegance to the garden in any season. Asparagus makes a big impact if the garden has enough space for it, but in smaller spaces one can enjoy the company of fennel. Bronze fennel is especially lovely with its chocolate-colored, feathery foliage that complements many other flowers and textures in the garden. During the cool season, dill and even carrot tops provide the perfect jade green lace to soften the bold leaves of red chard, blue cabbage, red mustard, or purple kale.
Purple coneflower (Echinacea purpurea), a resilient garden perennial, is famed for its medicinal qualities. Incredible heat tolerance and indifference to alkaline clay soil make it a favorite in my garden, even though the pink-and-orange flowers present an odd combination of colors. However, backed by the lacy blue foliage of rue or filigreed leaves of Artemisia ‘Powis Castle’ (one of the few silver wormwoods to thrive in our humidity), purple coneflower blossoms shine radiantly. A local form of this American native stays evergreen here and blooms from March to December most years. This treasure, named ‘Ida’, is being passed around to nurserymen for propagation.
Another popular medicinal herb, goldenseal (Hydrastis canadensis), hails from America’s woodlands, where it thrives in shade and rich, moist sandy soil. It makes a slowly spreading ground cover for poorly lit sites. Dwarf comfrey (Symphytum grandiflorum) makes the perfect consort for goldenseal in shaded beds but also survives in harsher sites of clay soil, drought, and some sun.
The double-flowering heirloom, soapwort (Saponaria officinalis ‘Plena’) also performs well in light shade, producing an abundance of soft pink flowers on 3-foot-tall stems. While not very showy, lemon balm (Melissa officinalis) is nevertheless a good contender for dry, shady parts of the garden where little else survives. It mixes well with cast-iron plant (Aspidistra elatior) and lilyturf (Liriope).
Pokeweed (Phytolacca americana) is frowned upon as a garden plant in regions where it is commonly seen along the roadside. Yet at the edge of its range, pokeweed is an uncommon delight with an imposing stature. Late summer sees pendant chains of purple-black berries adorning the reddish stems and large oval leaves, making it the perfect partner for a grouping of colorful ornamental peppers in the foreground. Easy-to-grow castor bean thrives in similar conditions, and the towering stems with large, maplelike foliage complement the vase shape and arching branches of the pokeweed.
Several mints persist in my garden, but never do they forge themselves into the kind of botanical war machine that one sees in northern gardens. Lavender mint (Mentha ¥piperita ‘Lavender’) is a delight to touch and smell, as the petite rounded leaves have a refreshing scent reminiscent of its namesake. The white variegated foliage of pineapple mint (M. suaveolens) is splendid weaving through the rich amethyst leaves of purple heart (Tradescantia pallida ‘Purpurea’). A robust clump of society garlic set amid the green, white, and purple foliage completes the picture.
Since most of the South sees some frost in winter, a few heat-loving plants are best grown in containers so that they may be brought indoors during cold weather. Tropical lemongrass (Cymbopogon citratus) is easily cultivated in pots and thrives in rich soil and consistent moisture. Although it has no showy flowers, it is the model of simple elegance and productive enough to share some leaves for the occasional Southeast Asian meal.
Medicinal aloe (Aloe vera) is one of a large genus of beautiful succulents that are structurally dramatic and carefree in containers. I am collecting several varied aloe species with prettier flowers or more architectural forms than the common medicine plant, but I nevertheless keep a pot of A. vera around to soothe the inevitable burns and bites.
As mentioned before, winter is a viable growing season for most of the South, with increasing numbers of possible plants as one moves close to the Gulf. Along with lettuce one can grow the opium poppy (Papaver somniferum), whose bold blue-green leaves add zest to the garden long before the colorful display of single and double gossamer blooms. Love-in-the-mist (Nigella damascena) also grows through winter in southern gardens, and its bright green filigreed leaves complement the foliage of the poppy as much as the flowers harmonize in bloom. Feverfew is another treat of the cool season, and the golden-leaved form is particularly beautiful combined with annuals mentioned above.
With attention to the details of sun and soil, most of these versatile herbs and more can be grown in even the smallest of southern gardens. Moreover, the culture of some of these treasures necessitates cool-season gardening since some plants thrive during winter months. Few others might require growing in pots for optimal performance. Without a doubt, designing gardens with herbs in the South is always a pleasure.
Designer and plantsman Tom Peace splits his time between Texas and Colorado. His book on southern gardening, published by Fulcrum Press, is scheduled to appear in bookstores in 2000.