In my last article I mentioned rain gardens as one of the elements of a sustainable garden. But what are rain gardens? Basically, rain gardens are shallow depressions designed to collect rain runoff, typically from impervious surfaces such as driveways and roofs. The intention of the depression is to allow the water to collect and percolate into the soil, allowing plants, bacteria and soils to clean and filter the water as it seeps into the ground.
A simple concept and very sustainable in ways that current systems of capturing and channeling rainwater into massive storm drainage systems are not, rain gardens do just the opposite by keeping stormwater close to where it falls. This helps to reduce flooding, allows sediments to settle and lowers the chances of stormwater becoming contaminated with oils and other chemicals.
So what is a properly designed rain garden? Consider the following criteria:
Location
Where you choose to locate your rain garden is important. Take the time to assess the existing conditions in your yard to determine the most appropriate place.
Locate the rain garden at least 10 feet from the house so water doesn’t seep into the foundation.
Do not place the rain garden over a septic system or near wells and underground utilities.
It is better to build the rain garden in full or partial sun in the open. Avoid big trees or areas of existing landscape you want to remain.
You can locate the rain garden within natural drainage patterns of your yard but not necessarily in an existing low area. The idea is to create new areas for infiltration to occur and it may be necessary to recontour areas of your yard to direct water to the garden. Consider that the garden will overflow in heavy rains, and sandy soils will percolate water faster than heavy clays. Amending clay soils with sand and organic matter will aid in infiltration.
Water should only pool in your rain garden for several hours after a rainfall before it is absorbed. This is important for both the plants as well as mosquito concerns.
Size
Typically rain gardens range from 100 to 400 square foot in size, but large gardens can run several thousand square feet. Your garden should be sized in proportion to your specific property conditions. While your individual rain garden may seem like a small contribution and not worth the effort, collectively, rain gardens can achieve significant water quality benefits.
Plants
It is best to use native, non-invasive plants that are able to tolerate periods of wet as well as dry conditions that will occur between (often long) stretches of no rain. Plants with extensive fibrous root systems such as native grasses, wildflowers and shrubs work well. Avoid turf grasses which do not absorb water as well as garden areas do.
Additional benefits
Consider not only the location and plants but also the overall design. A well designed rain garden will not only be a functional benefit to the ecosystem by helping to protect our water quality, but can also attract birds and butterflies, require less maintenance than traditional lawns and provide an interesting addition to your landscape. This will add beauty and value to your home.
Chuck Taylor, ASLA, is a practicing landscape architect and Campus Planner for Georgia Southern University. Chuck is the recipient of four design awards from the Georgia Chapter of the American Society of Landscape Architects, most recently for his pro bono design for Ogeechee Area Hospice and design work in creating a pedestrian friendly campus at Georgia Southern.
A simple concept and very sustainable in ways that current systems of capturing and channeling rainwater into massive storm drainage systems are not, rain gardens do just the opposite by keeping stormwater close to where it falls. This helps to reduce flooding, allows sediments to settle and lowers the chances of stormwater becoming contaminated with oils and other chemicals.
So what is a properly designed rain garden? Consider the following criteria:
Location
Where you choose to locate your rain garden is important. Take the time to assess the existing conditions in your yard to determine the most appropriate place.
Locate the rain garden at least 10 feet from the house so water doesn’t seep into the foundation.
Do not place the rain garden over a septic system or near wells and underground utilities.
It is better to build the rain garden in full or partial sun in the open. Avoid big trees or areas of existing landscape you want to remain.
You can locate the rain garden within natural drainage patterns of your yard but not necessarily in an existing low area. The idea is to create new areas for infiltration to occur and it may be necessary to recontour areas of your yard to direct water to the garden. Consider that the garden will overflow in heavy rains, and sandy soils will percolate water faster than heavy clays. Amending clay soils with sand and organic matter will aid in infiltration.
Water should only pool in your rain garden for several hours after a rainfall before it is absorbed. This is important for both the plants as well as mosquito concerns.
Size
Typically rain gardens range from 100 to 400 square foot in size, but large gardens can run several thousand square feet. Your garden should be sized in proportion to your specific property conditions. While your individual rain garden may seem like a small contribution and not worth the effort, collectively, rain gardens can achieve significant water quality benefits.
Plants
It is best to use native, non-invasive plants that are able to tolerate periods of wet as well as dry conditions that will occur between (often long) stretches of no rain. Plants with extensive fibrous root systems such as native grasses, wildflowers and shrubs work well. Avoid turf grasses which do not absorb water as well as garden areas do.
Additional benefits
Consider not only the location and plants but also the overall design. A well designed rain garden will not only be a functional benefit to the ecosystem by helping to protect our water quality, but can also attract birds and butterflies, require less maintenance than traditional lawns and provide an interesting addition to your landscape. This will add beauty and value to your home.
Chuck Taylor, ASLA, is a practicing landscape architect and Campus Planner for Georgia Southern University. Chuck is the recipient of four design awards from the Georgia Chapter of the American Society of Landscape Architects, most recently for his pro bono design for Ogeechee Area Hospice and design work in creating a pedestrian friendly campus at Georgia Southern.