Gardeners and landscapers are discovering what conservationists knew all along: native plants, once established, require less water, fertilizer and general effort than do non-native species. Native plants lived in places for generations before they were covered with lawns, perennial borders, vegetable gardens, buildings or parking lots. They are, happily, becoming more widely available as property owners invest in rain gardens, wetland gardens, woodland gardens and prairie gardens that reflect their area's natural heritage. Learn to identify and use native plants; they improve your landscape and reduce its carbon footprint.
Take walks in wild places--the mountains, seashores, a National Park or wildlife refuge. Chances are that much of the vegetation is native. Notice flower shapes and colors, shapes of leaves and sizes of plants. Native plants may show more differences in size or coloring within the same plant group because they have evolved over generations. Introduced species tend to be more uniform in size and coloring.
Find a local conservationist to show you his rain garden, restored prairie or project in a local park or arboretum. Ask which plants are native, and find out why certain plants were chosen for the project.
Join a Native Plant Society and participate in projects it offers. Dozens of organizations provide information about and sources for plants. Some provide assistance and incentives. Just some examples: Mid-Atlantic gardeners have a wonderful resource in the Alliance for Chesapeake Bay's Bayscapes program. The Minnesota Department of Natural Resources operates a "Native Prairie Bank" to provide credits for preservation.
Find a reliable data source; you will never remember all of the varieties of native plants. The wildflower data base at the Lady Bird Johnson Wildflower Center at Austin lists trees, shrubs, grasses and ferns as well as herbaceous plants. USDA Natural Resources Conservation Service provides distribution maps for each species in its data. Check your state's native plant society, too; many maintain useful catalogs and instructions for rain gardens and other special gardens.
Walk in the wild regularly, taking notes and drawing pictures in a notebook. When you arrive home, look up and label what you've discovered. You may start only knowing what a trillium looks like but soon you will easily identify dozens of plants just by observation.