by Carl Salsedo, Ph.D
Extension Educator, Horticulture
Non-native plants (also called non-indigenous, invasive or exotic plants) are plants that have been introduced into an ecosystem in which they did not evolve. Some of these plants are introduced deliberately, as with our many exotic landscaping plants. Others are introduced accidentally, through the spread of seed by wildlife or by their inadvertent inclusion in seed mixes being sent from one area of the world to another. Some of these introduced, non-native plant species do not grow well in their new environment or do not reproduce easily so they are controlled and pose no threat to the native ecosystem.
Other introduced species find their new home much to their liking and reproduce prolifically, even in natural, minimally managed landscapes. These aggressive, or invasive plants often have no natural enemies or controls to limit their spread. Invasive non-native plants species can be a serious threat to native plants and communities, out-competing local species for available sunlight, water and nutrients, and do not provide the wildlife habitat benefits of the plants they replace.