Plant Rain Gardens for Beauty and Water Protection - U of I Extension

News Release

Plant Rain Gardens for Beauty and Water Protection

This article was originally published on March 13, 2008 and expired on September 12, 2008. It is provided here for archival purposes and may contain dated information.

"Spring will soon be here and homeowners can help protect water quality and beautify their property at the same time, by planting a rain garden", says John Church, University of Illinois Extension Educator, Natural Resources, Rockford. A rain garden is a slightly sunken perennial garden that collects rainwater from a roof, lawn or paved area and allows it to seep into the soil, rather than letting it run off into storm sewers and, eventually, lakes and streams.

Researchers and educators have been planting and monitoring rain gardens for several years. One reason there has been more interest is that many people can feel frustrated by complex environmental problems and yet it seems there is little any one person can do to make a difference. A rain garden, however, is something an individual can do to have a positive impact on their individual and community environment. It is a way for people to do the right thing, plus have the added benefit of having a beautiful addition to a home.

Rain gardens differ from ordinary perennial gardens because they are planted in a somewhat shallow, flat-bottomed earthen bowl. They are usually planted with native perennial flowering deep-rooted plants. Popular choices include Sunflower, Black-eyed Susan, Liatris, Gay Feather, Blue Flag Iris, Purple Cone Flower, Cardinal Flower, and Golden Alexander. The gardens should have a mix of flowers that bloom at different times of the year for a steady show of color.

These gardens benefit the environment because they help increase the amount of water filtering into the ground instead of running off, helping to recharge groundwater and reduce the volume of stormwater runoff, which can reduce the amount of pollutants washing into lakes and streams. They can help also help provide wildlife habitat.

University of Wisconsin research has shown that a properly constructed 300 sq. ft. rain garden can absorb up to 12,000 gallons of stormwater annually. University of Minnesota researchers have found that the gardens can reduce phosphorous, nitrogen and sediment amounts by about fifty percent or more. Minnesota research also indicates that the gardens absorb about 30% more rainfall than turfgrass lawns.

Rain gardens should not be a breeding place for mosquitoes when designed correctly. Water should only stand in the depression for up to one or two days before it is absorbed into the soil, so mosquitoes eggs and larva cannot survive there. Standing water has to be present for at least seven days for mosquitoes to hatch. "If water is standing in the rain garden longer than a couple of days, there are design problems and it is not functioning as intended," says Church.

More information about how to construct and plant a rain garden is available in two University of Wisconsin-Extension publications: "Rain Gardens: A household way to improve water quality in your community" and "Rain Gardens: A how-to manual for homeowners." Both can be downloaded free of charge at http://clean-water.uwex.edu/pubs/raingarden/index.html. Rain garden and managing stormwater at home information is also available through University of Illinois Extension - Rockford Center website at http://web.extension.uiuc.edu/rockfordcenter/nre2130.html.

Source: John Church, Extension Educator, Natural Resources Management, churchj@illinois.edu

Pull date: September 12, 2008