This turned out to be the debate's most contentious issue. When we use these terms, we not only risk fanning the flames of xenophobia but also miss the point. Wolschke-Bulmahn raised the related issue of invasive natives, arguing that native plant enthusiasts should be more forthright about these problem plants. But this distinction between native and non-native invasives only makes sense when we use the strict, regional definition of native plant. This is just one reason why the debate convinced me that we need to be unequivocal about our definition of native plant.
Many gardeners consider any plant that grew in the U.S. before European settlement to be native.
But a wildflower that grew in the New Jersey pine barrens two hundred years ago is almost certainly not a native plant in a California garden, in an Oregon or even in a Georgia garden. New Frontiers I'd venture to say that someday nativeness won't be much of an issue at all. Someday we'll know enough about ecology to be able to create totally new plant communities, combining species from around the globe, that add to, rather than subtract from, the planet's wonderful variety of life forms. In these structures, no contaminated wastewater leaves the site. The frontiers of this new indoor gardening are largely unexplored.