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Kathy’s Garden Writing |
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GO NATIVE With so many exotic ornamentals offered by the gardening industry, why plant ordinary natives? Landscapers suggest many reasons – creating a sense of place, avoiding high maintenance imports, protecting native species from extinction, etc. But according to entomologist Douglas Tallamy, in his new edition of Bringing Nature Home, the native versus alien decision is most importantly about bugs. How so? Well, Tallamy maintains that insects are the linch pins essential to ecosystem biodiversity because they are directly or indirectly the most important food source for many higher organisms, including the birdlife we cherish. And bugs need plants to survive. In fact, insects are the world’s most efficient converters of plant energy into protein. But just any plant won’t do. Insects require plant species that were part of their evolutionary ecosystem. In other words, our local bugs often can’t eat alien plants – no surprise then that many of these imported ornamentals are advertised as “pest-free.” But isn’t this a gardener’s dream – no bugs? The problem is that a land without insects is also a land without most forms of higher life. To follow Tallamy’s argument, when you destroy native plant habitats, you evict the insects that feed on them, even some of our favorites like monarch and viceroy butterflies; and you ultimately eradicate all the living things that either directly or indirectly depend on these insects, like bluebirds and wood thrushes and the black-capped chickadee. What you get in place of these crucial native insects are aliens like Japanese beetles, gypsy moths, hemlock wooly adelgids, and azalea lace bugs. To add insult to injury, these pests have usually hitched a ride with imports by the nursery trade. So by continuing to plant non-native ornamentals, we are allowing alien insects, which can be truly destructive, to increase and multiply, while native insects are being starved into extinction. But if we attract native bugs to our gardens with native plants, won’t our plants look ragged and literally moth-eaten? Not likely, for Tallamy has also found that a healthy garden is in balance -- a living community, teeming with all sorts of insect herbivores, insect predators, birds, amphibians, and small animals. In addition, other researchers note that up to ten percent leaf damage can occur before the average gardener even notices. So if the native plant movement is critical environmentally, how can a small-scale backyard gardener make a significant contribution to the effort? Isn’t this a job for large tracts of conservation land? Well, actually, the home gardener can make a huge difference. To learn why and how, tune in next month as this plea for native plants in our backyards and gardens continues. Kathleen Arcuri Published in The Benton News, August 2, 2009 |