Well Dressed Garden: Perennial pleasures
Perennial plants, the classic stars of good gardens everywhere, aren't quite what they used to be -- they're better, and they are becoming more important. Popular perennials introduced recently are setting new standards beyond their good looks, toughness and reliability. They are defining the role of gardens in our lives.
"The classic perennial plants I rely on are drought tolerant, and they attract pollinators and provide nectar for bees and butterflies," says Janet Draper, horticulturist at the Mary Livingston Ripley Garden at the Smithsonian Gardens in Washington, D.C. "It's not just about me anymore," Draper says. These days, pollinator-friendly plants are being prioritized more highly than ever.
Habitat loss has put increasing pressure on insect populations, and gardens that attract pollinators help make up for the loss of wild nectar-rich plants that bees, butterflies and other pollinators depend on. Perennial plants, which, once established, come back every year -- usually bigger and stronger than the year before -- can be the backbone of a hard-working, long-blooming, pollinator-friendly garden.
One of Draper's favorite perennials is Calamintha White Cloud, "a bee's dream," she says, "for bees of all stripes -- from the little tiny guys to honeys and bumbles, all happily buzzing along all summer long." This plant makes gardeners happy, too. "It's a blooming machine," she says, a hardy, low-maintenance perennial that doesn't need pruning or pampering and isn't bothered by pests.
Draper is also the president of the Perennial Plant Association, and her list of favorite new perennials is long. She likes to pair the billowing White Cloud calamintha with the purple globe flowers of Allium Millenium, which was the PPA's plant of the year for 2018. She combines these two with the long-blooming Phlox paniculata Jeana, which was a stand-out in trials at Mt. Cuba Center, a botanical garden in Hockessin, Delaware. Jeana, which has pink flowers on 5-foot stems, blooms from July through October and attracts more butterflies than any other phlox. Draper calls the combination of Jeana phlox, Millenium allium and White Cloud calamintha "a pub for bees. They all like to hang out at the local pub," she says.
Brent Horvath, a hybridizer and the owner of the wholesale nursery Intrinsic Perennial Gardens, also gives high marks to summer-blooming alliums. His favorite is one of his own introductions, Summer Beauty, which begins to bloom in July in his garden in Illinois. He likes Summer Beauty for its flowers and for its long-lasting seed heads, which look great with little caps of snow in the winter. True classic perennials "have presence in the garden for four seasons," Horvath says.
Horvath and Draper are both smitten by perennials that contribute interesting textures to a garden, and ornamental grasses fill that bill with aplomb. Fountain grass, Red Head (Pennisetum alopecuroides Red Head) blooms a month earlier than other fountain grasses, Horvath says, with showy flower heads 8 inches long and 4 inches wide. When they're back-lit by the sun, they seem to glow. The abundant foliage of Hakon grass (Hakonechloa macra Aureola) brightens shady spots and "gives the feeling of flowing water," Draper says. She also relies on the vertical habit of reed grass (Calamagrostis Karl Foerster) for dramatic punctuation in the garden.
Durability, availability and performance year after year are the qualities Horvath insists on for classic perennials. Black-eyed Susans (Rudbeckia) come close, but many varieties are susceptible to foliage diseases. A new Rudbeckia called American Gold Rush has narrow leaves that resist disease, he says. The plants produce golden-yellow flowers with a distinctive dark center from mid-summer through frost. They thrive in the heat and humidity of the south and survive brutal winters in the north.
Reblooming and long-blooming perennials are the new standard, says Karl Batschke, product manager for Darwin Perennials, the company that introduced the colorful Sombrero series of coneflowers. Gardeners want their perennial flowers to bloom all summer long, just as many annual flowers do, "and we are getting closer and closer to that," he says. "There is a lot of cool new stuff coming along," including daisies (Leucanthemum) that bloom for three months and a summer-blooming candytuft (Iberis). New perennial lavenders and salvias on the market are good-looking, hardy and long-blooming, and pollinators find them attractive, too, Batschke says. "I grew up with annuals," he says, "but what I see now in perennials coming to market -- there's diversity and beauty, and they're all exceptional pollinator plants."
It appears that butterflies and bees are the beneficiaries of the latest perennial-plant introductions, but consumers can't complain. When new plants promote biological diversity and also knock your socks off with fabulously long bloom times and performance year after year, gardeners hit the jackpot.
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