Rain gardens have many benefits

November 14, 2009|By CELESTE MAIORANA / Special to The Herald-Mail

Rain gardens are shallow depressions formed to capture and soak up stormwater runoff from roofs or other impervious areas such as roads, driveways and sidewalks. They recharge groundwater, improve water quality, and buffer our waterways.

They are located in dug or natural low areas planted with suitable trees, shrubs, flowers and other plants. They help filter runoff; they settle and take up pollutants; and they allow water to seep back into the soil.

In addition to controlling runoff and improving water quality, rain gardens provide habitat for wildlife and, with a suitable selection of plants, increase the number and diversity of birds and butterflies. They provide an attractive and creative alternative to traditional lawn landscapes and require less maintenance, because they do not need to be mowed, fertilized or watered after they are established.

When implemented on a community or neighborhood scale, they reduce the load on storm-drain systems and help prevent flash flooding.


Originally, artificial rain gardens were created to mimic the water retention characteristics of depressions that occurred naturally before urban developments leveled and compacted soil.

Rain gardens for residential use were developed in 1990 in Prince George's County, Md., when a developer building a new housing subdivision decided to replace the traditional collection pond with shallow, planted depressions on each homesite. These rain gardens proved to be effective in controlling runoff and cheaper to install.

To install a rain garden at your home, survey your lawn during or after a rain. You might find an existing depression which can be developed into your garden, or you might need to dig one in a convenient spot. Sand and compost can be added to improve soil permeability. Plant selection is important. Plants must be able to tolerate both wet and dry soil conditions.

Native plants are preferable because they are most suited to the local soil and rainfall characteristics and are believed to be more beneficial to native birds, butterflies and other animals.

- Celeste Maiorana is a board member of the Washington County Forest Conservancy District, which promotes forest conservation in Washington County. For more information, go to

To learn more ...

For more information on design and plant selection, see:

o Rainscapes -

o University of Rhode Island healthy landscapes program -

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