Think Spring, Think Rain Gardens
Posted: February 27, 2011
Rain gardens are one form of “green landscaping,” which is a way of designing beautiful and healthy places to live while reducing environmental harm, saving time and money, and providing a habitat to wildlife. Green landscaping encourages natural landscapes that are less dependent on pesticides, fertilizers, and labor. This saves time and money when compared to maintaining a more formal landscape. Green landscapes provide habitats for more wildlife, require less frequent use of equipment that cause air pollution, and improve water quality by managing storm water runoff.
When it rains, rainwater flows over roofs, yards, and paved surfaces. As it does, it picks up a variety of pollutants, including fertilizers, pesticides, oil, trash, and animal waste. As it flows to our water sources, the rainwater mixed with these pollutants can be unhealthy and detrimental to people and wildlife. The primary function of rain gardens is to protect communities from this polluted runoff.
Rain gardens slow the flow of storm water, and filter pollutants before they are washed into our rivers and streams. “The primary purpose of rain gardens is to catch the first flush of toxins and other pollutants off a road, parking lot, or roof, and protect our drinking water and children from environmental pollution,” says Bryce Davis, owner of The Plant Place and Davis Organics in Elizabethtown, Pa. Along with these water quality benefits, use of native plants in rain gardens creates wildlife habitat and adds beauty to your backyard.
A rain garden is very similar to a traditional garden with a few main differences. It should be located in an area that can intercept storm water runoff flowing from your property. The ground should be slightly indented so that the water can flow into and fill the garden. It should be able to drain the collected water over several hours to several days, and it should contain plants that can handle being soaked with water.
When planning your rain garden there are several key details to consider, including garden size, soil type, location, design, and plant types. The size of the garden should be proportionate to the area from which the garden will collect runoff. A larger area from which runoff is collected should result in a larger garden that can hold and drain more water. Sandy soils will drain faster, so less surface area is necessary, while clayey soils drain more slowly, which will require a larger garden for more water storage.
The location of the garden should be on the downhill side of a property where water naturally flows, or where it can be diverted by a downspout. It is crucial that the garden is located at least 10 feet from building foundations, underground utilities, and septic units to avoid creating new problems on your property.
When selecting a garden design, it may be helpful to refer to the Low Impact Development Center, which provides templates for home landscaping. Here you can choose from various rain garden designs based on your own local region of the greater Chesapeake Bay Watershed.
The templates even provide suggestions for plants. Plants native to the region are best, especially those accustomed to wetter soils, which have already adapted to the region’s climate and soil conditions, and are likely to thrive with minimal care. Native plants of the Mid-Atlantic region suggested for rain gardens can be found at the Native Rain Garden site.
New to rain gardening and uncertain how your garden will behave? “It may be advisable to plant a seed mix that contains 30 or more species of plants,” suggests Karl Kerchner of the Lebanon County Conservation District. “If planted and maintained correctly, something is very likely to thrive."
"If an individual has a bit of willpower, and does not mind getting a bit dirty, he or she can construct a beauty of a rain garden within a weekend, with not all that much effort,” notes Kerchner. “Such facilities may be easily constructed, maintained and enjoyed by nearly anyone.” Homeowners should consult a professional or carefully follow a complete and comprehensive guide to ensure proper design, construction, and function.
We all live downstream. Water pollution affects the entire community, as well as surrounding communities, but each additional rain garden created can help reduce the amount of pollution reaching local streams and improve the water quality. “Sustainable is not good enough, restorative [action] is needed,” notes Davis. “That is why we need rain gardens – to help restore our watersheds.” We can all contribute to making a difference, one rain garden at a time.
To learn more, consider attending a Rain Garden Workshop. Extension, Conservation Districts and other conservation organizations may offer these workshops in your area.
For additional information, Please visit these resources:
- Rain Gardens for the Bay - Wisconsin Department of Natural Resources
- Alabama Master Gardeners Rain Garden Manual
- Virginia Department of Forestry
- Pennsylvania Storm Water BMP Manual, Chap 6, pg 49-61
- University of Connecticut, Cooperative Extension
For other green landscaping practices and related links, including composting, green roofs, and energy conservation through landscaping, visit the Mid-Atlantic Region Green Landscaping.
- Conewago Creek Initiative Intern