Every weekend, millions of Americans escape from their desks to enjoy one of the most popular hobbies: gardening. Fresh air and flowers, a little exercise, and a lot of time spent with green and growing things-is this a peaceful picture or a cause for conservation concern? Every year, the horticulture/nursery industry imports thousands of new species and cultivars of trees, shrubs, and other plants. Over the years, some of these invariably become invasive pests in some parts of the U.S.What do you do when one person's conservation problem is another person's livelihood? To many conservation professionals, dealing with non-native invasive plants is an eradication issue. Few are working directly at the source of the problem. Working at the source requires getting the attention and cooperation of a multibillion dollar industry whose lifeblood is continued importation of new plants. Dr. Sarah Reichard of the University of Washington's Center for Urban Horticulture is doing just that. Over the past thirteen years, she has worked with the horticultural industry not only to create awareness but also to change the way in which the nursery business operates. Her approach is a model for working positively with other industries on sensitive conservation issues.
The Scope of the ProblemGardeners on the lookout for the newest and best plants on the block drive the $11.2 billion horticulture/floriculture industry. In this highly competitive business, new plant introductions are key, and growers and breeders constantly need to seek out new cultivars, varieties, and species.Mail-order catalogs from specialty growers such as Forest Farm in Oregon or Heronswood in Washington will startle the uninitiated. These are not pretty color flyers of a dozen pages or so. They are densely printed botanic catalogs resembling a miniature New York City phone book, listing several thousand species of trees, shrubs, woody plants, grasses, and perennials.Many of these species are innocuous. But the behavior of plenty of newcomers is untested and potentially problematic in the varied climates of North America. In fact, whereas plants have been introduced for centuries for a variety of purposes, 85 percent of the non-native woody species that have naturalized themselves in this country-everything from eucalyptus to English ivy-were originally introduced for the landscape trade. Consider, for example, the estimate (1) that if ten percent of the world's 260,000 vascular plants are good colonizers, then at least 26,000 weedy species exist. At present, only about 4,000 of these have been distributed around the world, leaving the potential for some 22,000 additional weeds to be introduced.And for all practical purposes, we have left our door wide open. The U.S. Department of
