Rain Garden Basics
Courtesy of Fernbank Museum of Natural History
If you're a gardener, you know rain can be your best friend or your worst enemy. But did you know that you can plant gardens to make the best use of Mother Nature's moisture?
Rain gardens are designed to conserve fresh water by redirecting rainfall within your yard. If you live on a sloped property, this is a no-brainer, because installing strong native plants in the path of the runoff can both reduce the amount of water that reaches your house (helping to prevent flooding) and bring vibrant plant life to an otherwise empty plot on your property.
“Native plants are ideal to use in a rain garden because they require very little maintenance—they both absorb water and tolerate drought very well," says Chris Bean, vice president of education at Fernbank Museum of Natural History in Atlanta. "Using native plants in our rain garden promotes biodiversity and allows others to experience the natural beauty that is available right here in Georgia.”
Fernbank consulted with the Georgia Native Plant Society to choose a variety of drought-resistant plants that are also strong enough to withstand moving water. Your local garden society can inform you of the best plants to use in your rain garden, or you can also search on sites such as the Lady Bird Johnson Native Plant Database for North America.
The Fernbank Rain Garden is a great example of how rain gardens contribute to conservation and pollution control—a sustainability practice you can easily mimic with your own garden in a residential setting.
“Fernbank’s rain garden is designed to divert stormwater runoff from the parking lot through this landscape of rocks and native plant species," Bean says. "This slows down the water flow and allows the garden to filter pollutants like brake dust and oil out of the water before it enters local watersheds.”
The Fernbank Rain Garden redirects parking lot runoff into a garden of plant species that grow well in the region's warm climate. The strong stand of native plants (which may vary according to season) decreases the amount of water entering storm drains and helps reduce damage to streams by slowing down the dirty, fast-moving storm water that would otherwise rush into nearby watersheds. The storm water helps replenish the soil moisture in the rain garden and provide natural irrigation for the garden. In one year of average rainfall, the Fernbank Rain Garden can capture and clean up to 300,000 gallons of water!
A consumer campaign in Maryland, Rainscaping.org, is a partnership between local business and governments there who are working together to reduce runoff in the Chesapeake Bay area (see a variety of residential rain garden styles and other conservation designs here). For residential rain gardens, Rainscaping lists three priorities for water control and conservation:
Slow it down.
Spread it out.
Soak it in.
This is a mantra to remember if you're planting a rain garden at home. Rain gardens work on flat ground, as well as on sloped land, and may be designed take the shape of a "ditch" or pond when used to collect rainfall and prevent runoff. And not all rain gardens are full of rows of symmetrically planted flowers: Shrubs and marshy grasses surrounding by stones make great water stoppers.
While it's possible to achieve beautiful results when planting a rain garden, remember that rain gardens aren't just botanical beauty pageants! The plants have an important job to do, and planting them strategically can save you water, money and time.