Members of some nursery organizations fear that emphasis on natives will make many of their more exotic plants less desirable or even unsalable. To address these complex issues, let's first define some terms. Botanically, native plants are defined as those growing and reproducing in a specific site, state, region, or country without introduction. American native plants are generally considered those that grew without cultivation at the time of European settlement. Nonnative, or exotic, species are those that originate outside a particular site, state, region, or country.
Japanese plants grown in the U.S. are exotic.
Naturalized plants are those exotics able to perpetuate themselves in a new location without cultivation. When we define a plant as native, we must consider not only its geographical range, but also where it grows in that range, and under what conditions. An American native plant may not thrive in gardens across the continent any more than a plant from Europe or Japan will. Within any province, there are many variable conditions that influence which plants will grow and their growth habits. For example, the Eastern deciduous forest province stretches from Minnesota to Nova Scotia and south to Texas and Georgia, and annual rainfall varies from 55 to 27 inches.