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a drought-resistant flowering plant with white blooms
Admit it. The mass of violets and lobelia you planted last spring went into the ground without much thought to midsummer's long, dry days and nights. But it's July, and it's hot, St. Louis-style: humid, breezeless and nary a rain cloud in sight. The landscape looks like a dull green Brillo pad. Lugging a watering can or the hose around for an hour from border to bed to basket isn't your idea of quality free time. So what's the answer to drought-proofing your garden?
Go native. "Once you're in a drought, gardens either have resistance or they need a drink," says Missouri Botanical Garden chief horticulturalist Chip Tynan. "Native plants have to deal with drought, so if you grow more native species, or tropicals that reach their peak in late summer, you'll have plants with good drought resistance with minimal soil requirements."
Most people know soil preparation is crucial and that adding organic material (leaf compost, pine needles, vegetable waste) helps the soil retain moisture. One advantage of many drought-resistant species is their love of poor soils, which means mulching requirements are minimal to nonexistent. "For prairie plants like coneflowers, adding a lot of mulch to retain moisture will leave you with a rotted plant," Tynan says.
But the secret to a native plant's lesser water needs lies in its extensive root system. According to Grow Native!, a joint program of Missouri's agriculture and conservation departments, many warm-season indigenous plants have roots that run four to eight feet into the soil, compared to depths of a few inches for cool-season non-natives.
Revolutionizing the native perennial market is a category of new hybridizations sporting cultivar names. "Growers are selecting native plants and reproducing them in new colors and heights, adding cultivar names, such as Echinacea 'Orange Meadowbright' coneflowers," says Chris Kelley of Cottage Gardens in Piasa, Ill.
Sun perennials are the hottest of the hotties. Kelley's penchant for late-season gardens draws bursts of color by mixing tropicals in containers or into late-summer garden beds to liven their look. She expands the late-season blooming picture by supplementing with annuals and "tender perennials"--plants such as geraniums that in a more southerly zone are considered perennials, but here work like annuals that withstand St. Louis' heat and humidity, moving indoors at the end of the season.
Many people who shun heavy watering duties or those with limited space favor Cottage Gardens' approach. Three drought-tolerant choices: Baptisia "Carolina Moonlight," a tall, erect lupine look-alike; the woody-flowering shrub Itea "Henry's Garnet," with scarlet foliage in the fall; and Missouri-native columbine (aquilegia canadensis). "The hummingbirds arrive just in time for this red-and-yellow spring bloomer, and it is much easier to grow than the non-native varieties," Kelley says.
Tynan uses a similar plan in his own garden. "Switching at midsummer the focus of your garden to tropicals planted in containers--whether beautiful pots, massive planters or empty olive oil cans--gives great color with minimal amounts of water," he says.
Among Missouri natives on the Missouri Botanical Garden's "Plants of Merit" list:
Prairie dropseed (sporobolus heterolepsis), an outstanding crossover ornamental grass, grows pest-free 20 inches high, with good winter interest.
Toothed evening primrose, or sundrops, are low-growing, shrubby perennials that flourish in dry, gravelly soil. With narrow, lance-shaped leaves and four yellow-petaled blooms, this taprooted plant is very showy.
Begonia "Bepared" or "Dragon Red Wing" begonia, an annual happy in full sun or partial shade. Mexican Heather, often called "false heather." This tropical shrub blooms profusely.
"Cuphea" has tiny lavender flowers and glossy green stems and produces blooms until frost.
Verbena "Imagination" is a seed-cultivated annual with clustered violet-blue blooms that works equally well in containers or in-ground.
Notable, too, at the Kemper Center for Home Gardening's plantings is the "Perfecta Series" Scabiosa caucasia, or pincushion flower, with showy white blooms that butterflies can't resist. Along with a particular plant's soil requirements, look for drought-tolerance clues in the texture of a plant's leaves. Patrick McNulty of Houlihan Land Concepts says leathery, waxy or hairy leaf surfaces will have greater resistance in dry periods. "Hairy leaves act as a micro-climate, blocking wind and reducing the drying effect," he explains. They also reflect the sun's rays better, as do silvery hued leaves. Needle-like tiny leaves lose less water, while some leaves roll inward to retain moisture.
The standout ornamental and prairie grasses on McNulty's personal list:
"Prairie dropseed," for its golden tones and winter interest, especially paired with Russian sage.
Panicum "Dallas Blues."
Miscanthus "Adagio," or maiden grass, for its sun tolerance, dwarf height, pink blooms that turn white--all reasons for its "Plant of Merit" status.
Like their prairie-grass cousins, herbs like it on the dry side, offering small-spaces rewards. McNulty recommends lavender, edible sage and rosemary for fragrance and drought resistance.
Tightly linked by conservation-based water retention principles is a practice called rain gardening. Horticulturalists Monica and Simon Barker began Bowood Farms outside St. Louis more than 20 years ago. From that wholesale-only plant heaven, the Barkers opened a horticulture service in Clarksville, Mo., with an emphasis on native plants combined with ornamentals, many made viable using a rain garden.
"Basically, it's a storm water system to soak up rain runoff, using a catchment basin as a holding tank," Simon Barker explains. By excavating a small depression in the ground and channeling water into it, you can sustain different flowering and foliage species than might be possible otherwise. "They're great attractions for butterflies, and plants like cardinal flower, swamp milkweed, some native hibiscuses and rushes do extraordinarily well," he says.
So dread not the drought. With new cultivars bursting off the pages of next season's seed and garden catalogs, and an ever-growing commitment to Grow Native!-influenced garden habits, how will your 2006 garden grow? Wisely and beautifully, we hope.
