by Lindsay Bond Totten
Scripps Howard News Service
Good plants are where you find them. And American gardeners are discovering that an exploration of the magnificent flora of our own continent cannot only yield great plants for our gardens, but they can contribute an important sense of place.
Banish the notion of wildflowers as "weeds." If they were, gardens here would be without the likes of phlox, coneflower, penstemon, or liatris. Shade borders would miss heucheras and tiarellas. All are native American wildflowers.
Not only are native plants worth growing, they harbor a multitude of traits just waiting to be discovered or manipulated. Plant breeders do it all the time; that's how we get "improved" strains of annuals, vegetables, perennials and shrubs.
It comes as a surprise to many gardeners that native wildflowers have breeding potential. We're so accustomed to them "as is," we fail to see them as raw material for breeder's programs.
Just like other hardy perennials, native plants can be meticulously selected for important garden qualities like colorful foliage or double flowers. Occasionally, a keen-eyed observer will stumble upon something extraordinary in a garden or nursery production field--even a parking lot. Phlox paniculata 'David' (a terrific mildew resistant white garden phlox) was discovered in a parking lot planting bed near Philadelphia!
Botanists call these named versions of plants "cultivars" (short for "cultivated variety"). Adopted as part of a plant's correct botanical name, the cultivar name appears in single quotation marks following the plant's specific name.
A cultivar possesses some special trait (like mildew resistance in the case of Phlox 'David') that is lacking in the original species. In almost all cases, the plant must be cloned--reproduced by division or cuttings--to insure that the desirable trait persists.
Some cultivars of native plants are selected for compact habit. 'Purple Dome' New England aster is one popular example. Where others of its kind frequently need staking, 'Purple Dome' remains stocky and upright without support. 'October Skies', a beautiful late-blooming cultivar of aromatic aster, is both compact and drought tolerant.
In other species, disease resistance is what catches the eye. The ability to resist powdery mildew won Phlox 'David' Perennial Plant of the Year 2002 honors. Monarda didyma 'Jacob Cline', a tall scarlet clone of beebalm, has performed well in most areas of the country.
Some natives are a bit too boisterous for the garden. 'Miss Manners' obedient plant (Physostegia virginiana 'Miss Manners') is a welcome non-running, white-flowering form of that overly enthusiastic tribe.
At other times the reverse is true, and crossing two species can result in "hybrid vigor." Baptisia 'Purple Smoke' is one such hybrid. Its vigorous habit and bountiful dusty purple spires make it an outstanding garden specimen.
One of my all-time favorites heucheras, 'Montrose Ruby', is also a hybrid. Introduced in the 1980s by Nancy Goodwin, a talented North Carolina gardener, it was the first of a seemingly unrelenting stream of heucheras with burgundy and silver leaves. It's still one of the best, its dark tones mixing well with yellow and chartreuse foliaged plants, never failing to lend an air of quiet sophistication to a sunny or lightly shaded bed.
Another genus benefiting from hybridization is Lobelia. The scarlet cardinal flower (Lobelia cardinalis) and the great blue lobelia (Lobelia siphilitica ) have been crossed repeatedly. Look for these spectacular offspring: 'Grape Knee-Hi', 'Flamingo', and 'Ruby Slippers'.
Fewer cultivars of native woodland plants are available, with the notable exception of foamflower (Tiarella). Cultivars of this woodland wildflower are legion, with so many available that the names and differences get confusing. I'll forgo further discussion of foamflower, except to point out that some forms are "runners" and others are "clumpers." Be aware of which type you're buying. All perform best in moisture-retentive, organic soils.
Woodland phlox (Phlox divaricata) cultivars are also available in some numbers. 'Louisiana' (purple with a magenta eye) and 'Clouds of Perfume' (fragrant, ice-blue) are two excellent selections to get you started.
Some woodland gardeners draw the line at double flowers. The double white trillium cultivars now for sale (at very high prices) do seem to lack much of the simple grace of this cherished group. That said, a colony of the double form of bloodroot (Sanguinaria canadensis 'Multiplex') reminds me of a tiny sea of graceful water lilies when in bloom each spring. To each gardener his own.
(Lindsay Bond Totten, a horticulturist, writes about gardening for Scripps Howard News Service.)
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