Rain gardens are a natural or manmade depression area in the landscape, filled with moisture loving native plants. They are designed to capture water runoff offering these benefits:
- Beauty and biodiversity to your landscape
- Provides food, shelter and nesting sites for birds
- Attracts butterflies and other beneficial insects
- Filters polluted runoff water before it is returned to groundwater
- Helps to conserve and improve water quality
- Reduces maintenance, no mowing or watering required
Photo credit: Aaron Volkening on VisualHunt / CC BY
Storm water runoff is believed to be one of the biggest causes of pollution. It increases flooding potential and carries pollutants from streets, parking lots and lawns into local streams and lakes. This problem increases as our communities grow creating more impervious surfaces such as roofs, parking lots, sidewalks and highways.
So how do rain gardens work?
After a storm a rain garden fills with a few inches of rain that is filtered and absorbed back into the ground. With a rain garden this will occur within a couple days, rather than a storm drain which is immediate.
These areas are then planted with both shrubs and perennials that prefer to grow in moist locations.
Photo credit: Center for Neighborhood Technology on Visual Hunt / CC BY-SA
A rain garden should be located to intercept runoff from impervious areas. The soil should have adequate percolation rates and kept away from building foundations, utilities and septic systems. The size should be roughly 5-10% of the size of the impervious surface generating the runoff.
Photo credit: Aaron Volkening on Visualhunt.com / CC BY
The plant series American Beauties has a wonderful website and section dedicated to creating a rain garden. They also have a brochure with a list of perennials and shrubs suitable for planting in your rain garden. This brochure can be seen at: http://www.abnativeplants.com/page/Rain-Gardens