Bringing Nature Home: How You Can Sustain Wildlife with Native Plants

by Douglas W. Tallamy

When I first became interested in the impact of alien plants on our nation’s biodiversity, I was surprised to learn that the terms “native” and “alien” were controversial. Somewhat naively, I thought that when a plant found in China is sold in the United States as an ornamental, it can be classified as an “alien” without much debate. I was wrong. Recently a good friend insisted that if a plant has been in North America long enough, it can be considered a native, regardless of its evolutionary origins. Even more problematic is achieving consensus on the definition of a “native” plant. The broadest definition is also the most commonly employed: a native is any plant that historically grew in North America. Some people recognize that it’s a stretch to call a plant adapted to a California desert a native of New Jersey, but these same people happily consider all plants that grow east of the Mississippi as native to any area in the East. Maps of U.S. hardiness zones are often brought out to justify the “nativeness” of one species or another. By this reasoning, a plant adapted to zone 6 in Tennessee will serve as a fine native in the areas of Pennsylvania with a zone 6 climate.