A rain garden is a low maintenance landscape feature designed to capture runoff from your house, driveway and yard before it leaves your property. Plants in rain gardens hold onto the water so that it has time to seep into the ground instead of running into the street, sewer, or neighboring property. Rain garden plants reduce the amount of fertilizer and other chemicals that run off of your property, which protects rivers, streams and your drinking water supply, and other sensitive ecosystems.