วันจันทร์ที่ 17 ตุลาคม พ.ศ. 2554


The New York Times 

  • The Lure of Carnivorous Plants



  • ABOUT 200 million years ago, certain plants with strange leaves showed up on what became the eastern half of North America. Because they grew in marshy, infertile soil, they had to devise other ways to find nutrients. And so they began to catch and eat bugs.
    Flash-forward to today, and these carnivorous plants are now luring more than insects; they’re attracting adventurous gardeners.
    “Sales have increased every year since 2007,” said Jason Austin, the manager of RareFind Nursery in Jackson, N.J., and a man so passionate about carnivorous plants that he has a tattoo of one on his arm. Referring to a program he runs for customers interested in the plants, he added: “Our first workshop was in summer 2008. We did one that year. We now do 10 or so.”
    Of course, people have long been drawn to these weird but lovable plants, enthralled by visions of man-eaters out of “Little Shop of Horrors.” There’s the Venus’ flytrap, for instance, with its hinged leaves like tiny jaws that snap shut around its prey; the sundew, which attracts insects with beads of jewellike sticky gel on its leaves; and the bladderwort, which uses vacuum action to suck bugs into its underwater traps. These and other carnivorous plants (or “insectivorous,” as Darwin wrote in his 1875 book on them) have digestive enzymes that liquefy the captured prey so that the nutrients can be absorbed.
    But the basic requirements of these somewhat fussy plants have often been neglected by buyers. The finicky flytraps that were sold as novelties in gift shops rarely survived for very long, and Robert Hoffman, the owner of Fairweather Gardens nursery in Greenwich, N.J., remembers one seller of terrariums who advertised the baby carnivorous plants within them as “lasting longer than cut flowers.” (The plants have a long history of being misunderstood. Until 1815, botanists thought the hollow leaves were not traps for insects, but refuges.)The new interest stands that old attitude on its head. Nurseries are now emphasizing the plants’ needs, teaching gardeners proper techniques for their care and developing hybrids that increase the plants’ vigor and range of color and form. Concern about the conservation of native flora may be propelling this change, or maybe gardeners are just rising to a new horticultural challenge, but either way, these specimens are beginning to be recognized as the long-lived perennials they are rather than being seen as transient novelties.
    The change may well help sales. Like Mr. Austin, Mr. Hoffman has enjoyed a recent upsurge in buyers. “In 2010, we sold one or two of some of the varieties,” he said. “In 2011, we sold out — mostly to men and boys.”
    “What we discovered,” Mr. Austin said, “is that showing people how to succeed with these plants and increasing their knowledge base has helped tremendously.”
    In their new efforts, some nurseries are focusing on one particular carnivorous genera: Sarracenia, or the pitcher plants. They are among the easiest of carnivorous plants to grow.
    Sarracenia are attractive, funnel-shaped, often prettily veined plants with leaves and flowers in a wide spectrum of colors. Most have hoods above their flaring tubular leaves to keep rainwater out, and a spot of nectar at the base of the hoods to lure insects. The bugs land, slip on the slick surface and fall into the tubes, which have downward-facing hairs to thwart any escape attempts.
    Pitcher plants form clumps, with leaves emerging from a central rosette in spring or summer; they range from 6 to 36 inches tall. Most bloom in spring, and sometimes again in late summer. The plants also feature nodding flower stems with umbrella-shaped blossoms and dangling petals. The petals fall after pollination, but the plants’ fascinating ornamental fruits and the seeds within them persist right up until autumn.
    Like all carnivorous plants, pitchers have fairly specific requirements. “They need very acidic soil, full sun, constant moisture and cold temperatures in winter,” Mr. Austin said (that’s a pitcher plant flower on his arm). For moisture, rain or distilled water works best, he said; water that is alkaline or that contains purification chemicals, like most municipal water, can kill the plants. Finally, pitchers should not be fed, and especially not with commercial synthetic fertilizer (or raw hamburger, for that matter). Such products, he said, “mean death to them.”
    Still, Mr. Austin said, unlike Venus’ flytraps, sundews and other delicate and unpredictable carnivorous species, pitcher plants are not hard to grow if their needs are met. In his nursery workshop, he tells participants that by far the best way to meet those needs is to grow pitchers in containers. Why? Because watering can be controlled, and the planting medium can be made adequately acidic. (Mr. Austin uses weatherproof plastic planters, with a mix of 80 percent peat moss and 20 percent perlite or washed construction sand.)
    Because pitcher plants need a cold winter resting period, Mr. Austin recommends keeping the containers outside. With the possible exception of the Southern species, he said, there is no trouble doing so year-round in the North, even if the container freezes solid. (The plants will need occasional watering if snow or rain is sparse.) Gardeners who are nervous about harmful freezing and thawing can place the containers in holes in the ground and mulch the area with evergreen boughs.
    William Smith, 72, a retired civil engineer, has embraced the container idea with gusto. He has grown pitcher plants in pots, kiddie pools and even a raised concrete bed lined with rubber sheeting that he constructed on his property in Warren Grove, N.J., a bed he calls “the largest above-ground bog in North America.” (Gardeners call pitcher containers “bogs” because they simulate the damp conditions of their counterparts in nature.)
    Mr. Smith’s 300-square-foot bed, which requires 72 bales of peat moss, has room for 600 carnivorous plants. “I have every Sarracenia species,” he said. “And 50 hybrids.”
    Like Mr. Smith, Kathy Cantafio, 50, an office manager in Chatsworth, N.J., is captivated by the strange beauty of pitcher plants. “They come in so many colors,” she said, noting the plants’ variety and the variegation of the leaves. And “they’re digesting bugs.”
    She added: “You can grow houseplants or vegetables, but it is a whole new world to grow some things that are carnivorous.”
    A few plantsmen, like Tony Avent of Plant Delights Nursery, in Raleigh, N.C., have had success growing pitchers in the ground as well as in containers.
    “You don’t need a bog to grow these plants, as long as you do not let the soil dry out,” said Mr. Avent, who tends the plants in his display garden and sells a dozen varieties through his catalog.
    THE rising interest in pitcher plants accompanies a long decline in their natural habitats, once numerous throughout the Southeast. Hundreds of thousands of acres have been lost, as lumber companies clear-cut the land, sprayed herbicides and suppressed fires in order to grow pine trees for paper, said Ron Determann, the director of the Atlanta Botanical Garden’s Fuqua Conservatory. In the old days, natural fires kept the habitats in the condition the plants required — free of the tree stands that would dry the soil and shade the plants. But no longer.
    Gardens and conservancies are striving to counter the loss. The Atlanta Botanical Garden recently opened a conservation nursery on a 180-acre site in Gainesville, Ga., Mr. Determann said. It is a living gene bank of native species grown from seeds collected from all known mountain bog communities.
    “If anything ever happens to the wild populations,” Mr. Determann said, “we know we have backups to restore them.”
    Other conservation groups that are involved include the Center for Plant Conservation at the Missouri Botanical Garden in St. Louis, the North American Sarracenia Conservancy and the Carnivorous Plant Society.
    Another way Sarracenia is being preserved is “conservation through propagation”: nurseries propagate (and, of course, sell) the plants themselves, increasing their numbers. Growers have also been developing hybrids to bring new vigor to the plants, and to increase consumer choice.
    The “bug” hybrids, for example, were developed by Larry Mellichamp, a professor at the University of North Carolina at Charlotte, and the late Rob Gardner, who was a curator at the North Carolina Botanical Gardens. These sturdy, striking and compact pitcher plants are 8 to 12 inches tall and produce two flushes of vivid growth each growing season. The “bugs,” which may keep their color in winter, include Redbug (a robust grower with hooded, wine-red leaves), Doodlebug (which has cobra-shaped, bright copper-colored veining on cream leaves) and Junebug (which has vivid chartreuse pitchers).
    Not every hybrid has widespread appeal.
    “I haven’t found the bugs to be popular,” said Mr. Hoffman, of Fairweather Gardens nursery. His buyers, he said, gravitate toward the bigger pitcher plants, like Sarracenia flava, which can grow to be waist-high.
    As the hybrids are created and the workshops continue, newer efforts are emerging as well. Jason Austin and William Smith have formed a small venture to educate the public about carnivorous plants and consult on the making of bog gardens. The name for their endeavor, an acronym of the founders’ first and last names, fits the mission: JAWS.
     
    Where to Find Pitcher Plants
    A variety of nurseries sell the many-colored pitcher plant, which is among the easiest carnivorous plants to grow.
    RARE FIND NURSERY
    Propagates and sells both pitcher plant species and hybrids, and related Pine Barren natives. The nursery, located in Jackson, N.J., also conducts workshops on building and tending containers for growing these plants outdoors year-round. Information: (732) 833-0613 or rarefindnursery.com.
    FAIRWEATHER GARDENS
    Specializes in rare woody plants and selected herbaceous perennials. The nursery, in Greenwich, N.J., sells about a dozen pitcher plants; one is Sarracenia flava, which can reach 30 inches. Information: (856) 451-6261 or fairweathergardens.com.
    PLANT DELIGHTS
    The nursery, located in Raleigh, N.C., offers many rare and unusual plants, including more than a dozen Sarracenia species and hybrid varieties. The hybrids include the “bugs,” a series of colorful, sturdy plants 8 to 12 inches tall. Information: (919) 722-4794 or plantdelights.com.
    CALIFORNIA CARNIVORES
    The granddaddy of the carnivorous plant nurseries, the nursery, in Sebastopol, Calif., sells both tropical and winter-hardy pitcher plants. Information: (707) 824-0433 or californiacarnivores.com.
    NICHE GARDENS
    Specializes in native plants of the Southeast. The nursery, in Chapel Hill, N.C., sells such rare Sarracenia species as S. alata (often pale colored), S. psittacina (called the parrot pitcher plant for its hooded leaves) and a double-flowered variety of S. leucophylla called Tarnok. Information: (919) 967-0078 or nichegardens.com.
    DANCING OAKS NURSERY
    Stocks a half-dozen species and hybrids of pitcher plants. The nursery, in Monmouth, Ore., also sells hundreds of unusual cold-tender and hardy garden ornamentals. Information: (503) 838-6058 or dancingoaks.com.
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