The New Natives
Gardeners and plantsmen keep their eyes open for happy accidents of nature, and gardens are richer as a result.
Oriental wisterias are among the most beautiful flowering vines. Their fragrance and gracefulness are intoxicating. But in some parts of the U.S. (like the humid Southeast), I have seen them grow up and over the tops of pine trees, eventually taking the trees down with shade and weight. These wisterias require a good steward to prune away rampant growth, deadhead to prevent seed development, figure out how to get them to flower within a reasonable time after planting — plus know when to prune so as not to remove flower buds. This invasive plant is high-maintenance for responsible gardeners.
What about substituting native wisterias? American wisteria (Wisteria frutescens), has a fruity fragrance, purple or white flowers borne on new wood and reblooms sporadically through the summer. Flower heads are no more than four or five inches long.
But not all American wisterias are equal when it comes to garden worthiness. 'Longwood Purple' flowers abundantly for me. The origins are lost but it was known to have been at Longwood Gardens in Pennsylvania since the 1950s. 'Amethyst Falls' flowers equally abundantly for me but about 10 days later and has lighter purple flowers. Both have been growing up my deck for years. I have not seen a seedling anywhere in my garden, and they have not pulled down the deck yet.
The native wisterias are remarkable in environmental tolerance. Kentucky wisteria (Wisteria macrostachya), grows from the bayous of Louisiana all the way to Minnesota, but if you want to be sure to get a good one for your climate, you should get a cultivar. Flowers are larger (18 inches) and more pendulous than those on American wisteria but still nothing compared to the four-foot chains of some oriental cultivars. Blue-flowered 'Aunt Dee' was found growing at the Bloomington Garden Center in Minnesota; it is Minnesota hardy. White-flowered 'Clara Mack' was spotted growing in a distinctly warmer garden near Columbia, S.C. Neither of these cultivars was found within the native range of Kentucky wisteria, but they had found their way to a new home. Gardeners recognized their merits and decided to share them.
Often gardeners covet what they think they can't grow. When I visited Charleston, Savannah and warmer areas of North Carolina in late winter or early spring, I would see the native Carolina jessamine (Gelsemium sempervirens), climbing its way through the roadside woodlands, often covered with little yellow flowers. From colonial days, gardeners have appreciated this mostly evergreen native vine, so it quickly found its way to southern arbors and trellises. However, it just wasn't hardy in my mountain garden.
A few years ago I was told about an allegedly hardy selection of yellow jessamine and decided to add it to the trials at North Carolina State University's Mountain Horticultural Crops Research Station. Honestly, I didn't expect 'Margarita' to live through the winter. The next spring, not only was it alive but it had developed into a vine with spectacular flowers.
Dr. Dick Lighty, plantsman and retired director of Mt. Cuba Center in Delaware, says that 'Margarita' is a superior seedling selected by Don Jacobs of Eco Gardens in Decatur, Ga. With its much larger, more prominent flowers, it was superior in every way to common seedlings, so Jacobs named it for his wife. He had no idea that it would survive winters to minus 25 F. as it has in Pennsylvania. This year 'Margarita' is a Styer award winner from the Pennsylvania Horticultural Society.
Happy discoveries have happened with coneflowers too — such as one with squilled (rolled up) petals. It was found by Henry Eilers when he was walking along a railroad right-of-way through some native prairies in southern Illinois. He brought it home, propagated it and somehow it came to nurseryman Larry Lowman in Arkansas, who has shared it with his fortunate friends. In my garden, Rudbeckia subtomentosa 'Henry Eilers' is about three feet tall and the flowers seem to glisten as if lit from within on cloudy days. Don't be fooled by the common name, sweet coneflower. The flowers aren't fragrant but when the leaves wilt, they give off a sweet fragrance.
A revolution is happening with the traditional coneflowers of commerce, Echinacea. Medicinal demand for this native genus have severely depleted natural populations of diverse species in the prairie states due to overcollecting. In other areas, habitat destruction has been consuming natural coneflower areas. Fortunately, many Echinaceas are good garden plants.
Purple coneflower (Echinacea purpurea) is best known to gardeners. It has a fibrous root system which should adapt better to the non-prairie soils in many of our gardens. When grown from seed, however, the flower form, color and habit aren't always attractive. To compensate for this natural diversity, seedsmen isolated the best parents to prevent random pollination. As a result, gardeners can now grow wonderfully consistent plants from seed, given specific cultivars. This process is what gave us the deeply colored 'Bright Star' (Starlight) with reflexed petals and 'Ruby Star' with horizontal petals, both dependable from seed. 'Magnus', once selected as the Perennial Plant of the Year, doesn't reproduce true from seed.
To be sure that every plant will look like every other, you need to work with clones. Some years ago nurserywoman Kim Hawks noticed some naturally dwarf coneflowers within a batch of Echinacea seedlings and kept working with them until she got a plant that was consistently shorter and flowered prolifically. In fertile soils, 'Kim's Knee High' may be thigh-high while some seedling Echinacea in my gardens have been taller than me in bloom (I am 6 ft. 2 in.) before they fell over. A few years later she and Sunny Border Nurseries introduced white-flowered Echinacea 'Kim's Mop Head'.
Pink and white flowers weren't enough for some gardeners and plant breeders. Dr. Jim Ault at Chicago Botanic Garden has been hybridizing multiple native Echinacea species for a decade. His first introduction, Orange Meadowbrite, has been described as true tangerine as well as blood-orange. In my garden, pink and orange sometimes appear in the same petal, and color seems to change with the light. At first I didn't think this hue would work in my borders, and I also worried how it would handle red-clay soil and abundant rainfall. Fortunately, rather than clashing, Orange Meadowbrite's color blends with a mixed border, and the plants have gotten stronger each year. Another Echinacea from Dr. Ault, Mango Meadowbrite, is the perfect golden yellow to blend with blue flowers like the catmints.
Richard Sauls of ItSaul Plants in Georgia has been creating coneflowers with a different look. His plants appear more robust, with broader petals and sometimes very large flowers. 'Sunset' and 'Sunrise' aren't in my garden yet, but they should be well adapted since they have even more purple-coneflower parentage than Dr. Ault's plants. 'Sunset' is reported to open coral-orange and mature to tangerine-orange. 'Sunrise' opens deep yellow and matures to a lighter buttery yellow with four- to five-inch diameter flowers.
Are these hybrids still natives? All of their parents are natives. The difference is that man moved the pollen between plants rather than bees. Accelerated evolution? Who knows? What I do know is that these are just the beginning when it comes to exciting new coneflowers. There are other colors, forms and even a dwarf on the horizon. Stay tuned!
Are Native Plants Better?
Native plants are often the only logical solution when it comes to planting. If you are gardening where there has been little building or soil disturbance, they might be right for you. Certainly, if you're restoring an ecological community, you'd want to pick site-specific and well-adapted natives. But when I hear someone say that natives are the only choice for gardens, I have to wonder what is meant. For example, native plants certainly have some pest resistance, but often pests have evolved right along with a native plant, or an exotic pest has been introduced. All natives are not pest-resistant.
A pest-resistant native plant — such as a powdery-mildew-resistant garden phlox or bee balm — may need to be a named variety (cultivar) because seedling grown plants have proven to be mostly highly susceptible to this disease. If you have a particular color in mind for your garden, larger flowers or a particular form like weeping or a plant with variegated leaves, a native that has been selected for these characteristics, a hybrid of a native or even an exotic plant may be just what you want. It is your garden, so plant what works for you.
Dick Bir is a horticulturist and conservationist as well as faculty emeritus from the Department of Horticultural Science at North Carolina State University. He serves on the North Carolina Plant Conservation Board and was a pioneer in the revival of native plants education and research. In retirement he reads, gardens, lectures, writes, consults, does housework and meddles.