Classic Perennials updated for today’s garden
by Jo Ann Gardner

Thanks to breeding breakthroughs and serendipitous discoveries, many of grandma’s favorite perennials are better suited to the needs of today’s gardeners.

Certain perennial plants have been popular in American gardens for decades; some of them, such as pinks (Dianthus spp.), go back to Colonial times. And many old favorites among bellflowers, phlox, and Shasta daisies, to mention a few, have been challenged over the years by the introduction of new “improved” varieties. As a person who loves older plants, I am cautious when it comes to growing “improved” versions. But if the new is really better without sacrificing the charms of the old, then I am all for it.
Not all change, however, is for the better, and many new varieties fall short of expectations. But certain introductions have added to the value of the original, by increasing adaptability or disease resistance, extending the flowering season or range of colors, or improving the form or foliage. Some of these varieties are new; others have been around long enough that they could almost be considered classics themselves.

Heat Resistance

What could possibly make pinks more appealing? How about a strengthened constitution so they look good longer? Among newer pinks are those bred for adaptability to hot and humid conditions, and, as a bonus, some are longer blooming than usual.

A cheddar pink (D. gratianopolitanus, USDA Hardiness Zones 4–8, AHS Heat Zones 8–1) hybrid worth considering is ‘Feuerhexe’ (Firewitch), chosen by the Perennial Plant Association (PPA) as the 2006 Perennial Plant of the Year. It has everything you could want in a pink: spicy fragrance, colorful magenta-pink flowers over silver-blue mats of foliage, a long flowering season, and excellent heat tolerance in the south. In the north, it has shown a remarkable ability to grow in less than ideal conditions, such as gritty, sharply drained soil…

Like pinks, bellflowers (Campanula spp.) have been grown in American gardens since Colonial times. So what’s new? A quiet revolution in bellflower breeding is under way. Led by Terra Nova Nurseries in Canby, Oregon, bellflower breeders are using C. punctata as a parent because it is more resistant to heat and humidity than taller types. Southern gardeners will be pleased with the results: ‘Pantaloons’ sports semi-double purplish-pink bells above deep green leaves; ‘Kent Belle’, which grows to 30 inches, produces very showy, long, dark violet-blue bells; ‘Bowl of Cherries’ is a compact, mounding plant with a multitude of purple-red dangling bells. All of these thrive in Zones 5–9, 8–1.…

New Millennium delphiniums (Delphinium hybrids, Zones 3–7, 8–3) have answered the consumer demand for longer-lived, less temperamental plants. Bred by Dowdeswell’s Delphiniums in New Zealand, they are said to have stronger stems, more heavily petaled, showier flowers, and improved tolerance for heat, humidity, and extreme cold. …

Drought tolerance

Who would have thought that moisture-loving astilbes could be drought tolerant? The most significant breeding within this genus, introduced from Asia in the 1850s, was achieved by German nurseryman Georg Arends, whose 1902 introduction ‘Peach Blossom’ set the standard for astilbes. ‘Peach Blossom’ and other classic cultivars of Astilbe 5arendsii (Zones 3–8, 8–1)—such as the fragrant white-flowered ‘Bridal Veil’, clear pink ‘Cattleya’, and vivid red ‘Fanal’—continue to be favorites for shady sites with moisture-retentive soil.

Newer introductions of selections derived from A. chinensis (Zones 4–8, 8–2) have expanded the possibilities of growing astilbes in drier conditions. Nancy DuBrule-Clemente, owner of Natureworks, a specialty garden center in Northford, Connecticut, appreciates great plants that can take care of themselves. High on her list are the A. chinensis hybrids, which can grow in heavy clay. She describes ‘Pumila’ (sometimes listed as var. pumila) as a “totally drought tolerant” workhorse that grows well in both sun and shade. Only a foot tall, it makes a great trouble-free groundcover…

Disease Resistance

Native garden phlox (Phlox paniculata, Zones 4–8, 8–1), queen of the mid- to late-summer flower border, did not become popular in American gardens until the late 19th century, after the species had been prettied up by the efforts of French nurseryman Victor Lemoine and others.

Although many older cultivars are no longer available, you will find some of them at Perennial Pleasures Nursery in East Hardwick, Vermont, where proprietor Rachel Kane carries many garden phlox, old and new. When comparing the newer phlox to the older ones, Kane feels that flower color and length of bloom are not an issue. As for powdery mildew, although some varieties are more susceptible than others (whether old or new), her advice is to divide plants regularly, replant in fresh enriched soil, and keep them well watered. Planting phlox in moist, well-drained soil, similar to their wild habitat, also helps. ‘David’, the PPA’s 2002 plant of the year, is without question one of the best for mildew tolerance. Growing four to five feet tall, with fragrant white blossoms that bloom from midsummer to frost, it has all the attributes we value in this favorite flower, and it has proven successful all over the country.

More Color, Better Form

The Shasta daisy (Leucanthemum 5superbum, Zones 5–8, 8–1) has a long history of popularity in American gardens. Created by Luther Burbank, it possesses the ideals that fueled his breeding efforts: large daisy flowers with pristine white petals held on sturdy stems and produced over a lengthy period. Named for the mountain in California near where Burbank worked, the first-named introductions in 1904 included ‘Alaska’, still the standard by which all other cultivars are judged.
Ironically, one of the most recent, ‘Broadway Lights’, is widely touted for its yellow flowers. Yellowish or cream-white Shastas seem like a contradiction, since Burbank strove so hard to produce a pure white flower.…

Daylily Updates

Among daylilies (Hemerocallis spp.), ‘Hyperion’, an early hybrid (1924), is still loved for its clean lemon-yellow trumpet, extended bloom, and fragrance. After World War II, daylily breeding took off and there are now 40,000 registered cultivars that often depart from the classic form with their recurved petals, narrow and spidery or overlapping, often heavily ruffled, in colors that range from near white with shades and mixtures of peach, pink, and purple. Flowers, eyed and with contrasting throats, can be huge, to eight-and-a-half inches in diameter, and dusted with gold or silver.

Ask experts about their favorite updates and their answers are an eclectic mix of types…


Photo credit: ‘Innocence’ delphinium by Terry Dowdeswell; Campanula ‘Sarastro’ by David Cavagnaro; Astilbe chinensis ‘Pumila’ by Michael S. Thompson

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