A lot of my gardening inspiration comes from visiting botanical gardens around the world in my travels with Peter. This column is being written while we are on the road with the Missouri Botanical Garden group in southern China. In this part of the world— Yunnan—there are images of elephants everywhere: in fresco, embroidery and sculpture. No live ones have presented themselves to us on this trip, but we have seen some stunningly huge annuals and perennials in these warm, tropical garden zones. Combining these two thoughts brought to mind the lyrics of Oklahoma with the line, “The corn is as high as an elephant’s eye.” So, with inspiration from the gardens at our sister institutions in Xishuangbanna and Kunming, Julie and I have selected a suite of bodacious specimens for the back of the border or center of a very large planting island.
These are not plants for the timid or the small garden. The selections on this list run from a low of 4 or 5 feet to more than 20 feet in height. While not restricting the list to only Chinese plants, I have thrown in several just for fun.
Chinese and Tropical Treasures
The first Chinese plant is the elegant, stately hollyhock. In the U.S., hollyhock is a true old-fashioned pass-along plant and a staple of cottage and country gardens for years. While they do have their share of problems, like rust and weevils, they are well worth the effort for that beautiful flower stalk towering over your border. Some of the new cultivars are rust-resistant: Try ‘Crème de Cassis’ in dark claret red with a white edge, ‘Peaches ‘n’ Dreams,’ a double with soft orange sherbet blooms, or the fade-proof ‘Black Night’ (deep black purple). These elegant, long-blooming hollyhocks are a beacon for butterflies.
My crazy plant-nut classmate Tony Avent suggests ‘Jonesboro Giant’ ironweed (Vernonia altissima), a wild-collected clone he found in Arkansas. He chose it for its strong, upright stems and heavy show of rich purple mini-puff flowers. The large clusters are so attractive, they draw hummingbirds from the next county. As a native plant, ironweed will perform very well in our locale, but beware, this one can top out at almost 12 feet once established.
If you are ready for a truly huge specimen, an anchor for a 50-foot bed, try the spectacular hardy sugar cane. This late-flowering specimen grass makes clumps up to 10 feet high and 10 feet across. The elegant gray-green arching leaves are graced with a crown of pink featherduster plumes that flutter in the breeze.
There is a banana that is reliably hardy here, Musa basjoo, that is a lot of fun to have towering over the back border and fluttering in the breeze. The broad-bladed leaves add a decadently tropical effect near a pool or water feature. As our local climate gets warmer, some of the other banana varieties will begin to overwinter. Julie coaxed a Musa zebrine through this past mild winter with the help of a heavy layer of mulch. All ornamental bananas may be grown in large urns and moved in and out with the seasons if you have a conservatory or other bright window for overwintering. Friends have had good luck simply digging and drying the root stock for a few days, then storing them in burlap wrappings in a cool, but not freezing basement or garage.
The giant cannas run anywhere from 4 to 10 feet high. ‘Black Knight’ has rich mahogany foliage and a glowing red flower and hits about 4 feet. Slightly taller, but in the same red scheme, is the old classic ‘King Humbert.’ Remember to dig and save all cannas for the winter in damp burlap in a cool, dark spot.
Lilies and Daylilies
The Chinese trumpet lilies have given rise to many Asiatic heritage cultivars. Try ‘Pink Perfection,’ a rich rose with yellow stamens (4 to 6 feet) or ‘Lollipop,’ a white center with dramatic ruby red tips (4 feet). ‘Regale’ is a trumpet form in rose maroon shades with a pure white interior. ‘Album’ has a white reverse with a clear yellow throat, and ‘Golden Splendour’ is a golden yellow sporting anthers one shade darker.
‘Scarlet Delight’ is a new hybrid with oriental and trumpet lily parents. It has a wide open face with ruby red petals edged with narrow white rims. Third year clumps can approach 6 feet.
Lilium martagon, the pink martagon lily, towered over my head in my grandmother’s garden. It is no new flash in the pan, but a triedand- true naturalizer that needs no pampering. The petite rosy buds open wide at first, but like a ballerina in pose, the petals re-curve quickly into a flower that faces out but wraps backwards gracefully toward the stem. It will look very much at home at the edges of a wooded garden. A classic.
Daylily foliage will never put it in the giant height class, but the flowers of some varieties will rise above the rest. Hemerocallis citrina ‘Yao Ming’ is a new cultivar from China that produces flowerscapes more than 5 feet tall. Named for the basketball superstar, the blossoms are a luscious golden yellow.
Native Missouri Giants
One of our most spectacular super-sized natives is the aptly named Queen of the Prairie (Filipendula rubra). In the right spot, moist soil with full sun, a well-established plant can easily run 6 to 8 feet. Several other cultivars and species are available, often called meadowsweet, but they are little pikers compared to the stately Queen. All of them carry very fragrant blossoms through most of the summer.
For a burst of yellow in the autumn garden, try ‘Henry Eilers’ coneflower. The petals of this cultivar are curved under on the edges, giving the flowers a spider-like appearance. Great for cutting, I pinch it back so I can reach them. If unpinched, you must stake it to keep it upright.
Julie and I both love the soft, fuzzy, gray leaves of the great mullein, Verbascum thapsus. A biennial, it starts the first year with a large rosette of leaves that resemble lambs ears. The second season, it throws up a giant silver flower spike filled with small primrose yellow blossoms. Stalks may reach 8 feet in height. One mullein can produce more than 100,000 seeds. If you grow wooly mullein in your garden, it is critical to remove the seed pods before they ripen.
There are special plants from all regions of the globe that punctuate the back border with elegance, grace and panache: Bells of Ireland, Texas Star hibiscus, Chinese anemones, European delphiniums, tall Japanese chrysanthemums, Mexican cosmos, amaranths and the giant brilliant red brushes of the Chinese celosias. I love the flowering tobacco (Nicotiana sylvestris), sometimes called jasmine tobacco, for its sweet night fragrance. It reminds me of the sultry summer nights of my own home region in the foothills of North Carolina.