A rain garden is a shallow depression (either natural or man-made) designed to collect and absorb storm water runoff from your roof or other impermeable areas around your home like your driveway, sidewalk, or even compacted lawn areas.
Your rain garden should be placed where runoff from these areas goes. It is designed to take flooding and should be planted with suitable trees, shrubs, perennials, and other plants that can tolerate periods of flooding as well as periods of dryness.
Storm water runoff often carries pesticides, heavy metals, salts, and other toxins. Rain garden plants are specifically selected bioremediators which means their roots and foliage can tie up these pollutants thus filtering the runoff and allowing this “cleaner” water to slowly seep back into the groundwater.
The following is a list of plants that make excellent rain garden plants. Many are native species.