Lower Minnesota River Watershed District

One of the 17 raingardens that the City of Burnsville and the Met Council funded in 2002-2004. The gardens cut down stormwater discharge into Crystal Lake by about 90% — not to mention added tremendous beauty and pride of ownership. Click photo above to go to article about the project. (Both photo and article by Barr Engineering.)

A second Burnsville raingarden. Photo: Barr Engineering.

A third Burnsville raingarden: note the curb cut that allows stormwater to run into the garden before it hits the sewers. Photo: Barr Engineering.

A less ornate raingarden in the city of Maplewood, in Ramsey County, features native plants. Click on the photo above or the two below to go to the city's web pages on these raingardens..

A Maplewood raingarden featuring sunny border plants.

This simple Maplewood garden, trenched in a swale at a corner, features hydrangeas and other familiar Minnesota shrubs.

This garden, off a commercial parking lot at the 7Sigma Corporation in Minneapolis, represents what environmentally (and esthetically) conscious companies can do. Click on image for more information.

Beautify and improve your property with a raingarden

What is a raingarden?

Ever wonder about impervious surfaces?

No, we don’t mean your slow neighbors! We mean the parts of your urban lots that were nature not so long ago but now are covered by concrete, asphalt, shingles, and other materials that prevent rainwater from permeating the earth.

In spring and summer, unchecked rainwater rushes from developed areas into drain pipes, lakes, and streams; and this rapid movement causes both erosion and pollution, carrying sediment and manmade pollutants like phosphates, salts, oils, and trash. (Fertilizer phosphates make algae bloom and cut off oxygen for diverse aquatic life forms.)

The good news about impervious surfaces is that even as man has created them we can mitigate their effects — and have fun doing so.

Raingardens are one of the “green initiatives” we’re hearing more and more about these days. (Others include rain barrels, porous driveways and patios, and green roofs.)

The New England aster, one of many colorful and easy-to-care-for raingarden plants.

The lavishly illustrated and clearly written Blue Thumb Guide to Raingardens is available through Metro Blooms raingarden workshops or Yahoo (see list below).

But what exactly are raingardens, and why should we give a New England aster about ‘em?

Raingarden workshops

Simply put, as landscape ecologist Rusty Schmidt suggests in the raingarden workshops he conducts for Metro Blooms (go to www.metroblooms.org), a raingarden is “a low spot, scooped out of the earth, six to 17 inches deep, that holds rainwater for just a day and cleans it up.” A rain garden is not a pond or a wetland, but a basin planted with deep-rooted plans that scrub or filter pollutants from rainwater before it is discharged via storm sewers to our lakes and rivers.

The most common placement of a raingarden may be next to a paved surface like a driveway, street, alley, or sidewalk. If the garden is not fed by water rushing over such surfaces, it may get water via a house’s gutters, perhaps after being sluiced from rainbarrels and underground pipes.

As the workshops stress, It's important to properly prepare the soil so that water infiltrates and doesn't merely stand and drown the plants.

How can you build a raingarden?

To set up your raingarden for proper water infiltration, you need to do a little planning.

If you attend the Metro Bloom raingarden workshops, these folks will give you guidance, from the planning at the start through the cultivation and care of your garden.

At the workshop, you can buy for just $10 the very handsomely illustrated how-to Blue Thumb Guide to Raingardens: Design and Installation for Homeowners in the Upper Midwest, authored by Rusty Schmidt and others. (The Watershed District underwrote the cost of publication for this year’s run.) Or you can order the book via raingardens@yahoo.com.)

First, test your soil and your drainage

As the book tells, the first step is to conduct a simple infiltration test to establish how porous your soil is. If your soil conducts water well, you may not need soil amendments. If you have a heavy clay soil, you may need to add compost or peat moss to loosen the soil. If you have a lot of sand, such amendments can help keep the moisture in.

You'd also be well advised to conduct a soil test, either through a local landscape person or on your own. (You can use a soil kit from the U of M Extension Service. Go online at http://soiltest.cfans.umn.edu/index.htm for information.) Without soils that will let water leach through, your raingarden won't work. This might be the case if your subsoils are sealed by clay or if they're highly compacted.

Your garden must not drain towards your house, but away. A good rule of thumb, says Schmidt, is locate the gaden at least 20 feet from your foundation. Other than that, you can put the garden just about anywhere — going down a hill or on a curb or boulevard. It can be fed by rainwater that sluices down from a driveway or a lawn, or from a series of rainbarrels that you've planted near your downspouts.

Besides the Blue Thumb Guide, you can also find lots of good materials on the web. See the list at the end of this article.

See what native plants you can find

Once you’re ready to plant, you’ll probably use mostly native plants, whether grasses, sedges, bushes, or flowers, as these are most adaptable to native soils and require little or no fertilizer or watering. (Natural Shore Technologies — see list below — is one good local source for such plants.) After the first year or so, once your garden is established, it should not require much care.

How can you afford a raingarden?

Some local Water Management Organizations (WMOs) are sponsoring cost-share initiatives to help you afford a raingarden.

Scott County. If you live in Scott County, you can apply to the Scott Soil and Water Conservation District for technical assistance. Financial assistance up to 50% of the cost of a project may also be available. Call 952-492-5425 for details.
Dakota County. Contact Jim Davidson, Urban Conservationist, at the Dakota County Soil and Water Conservation District at 651-480-7779. An overview of the county's community conservation cost share program is available in the list below.
Nine Mile Creek Watershed District. If you live in this watershed district, which includes parts of Bloomington, Eden Prairie, Edina, Hopkins, Minnetonka, and Richfield, you can also qualify for up to 75% match on materials and labor, up to a maximum of $3,000. (Click the link below to access the information and application.)
Your city. You might also try calling your local municipality and inquiring what grants and cost-sharing programs they might know about for enhancing your yard’s beauty and doing the environment a big favor. Savage is one muni that will help citizens and organizations with raingardens.
Metro Blooms. This nonprofit, which sponsors the raingarden workshops, will reimburse you up to $65 for the plants that go into a raingarden. Contact Executive Director Becky Rice for the application: becky@metroblooms.org.

Links to more raingarden information

“Burnsville Rainwater Gardens.” Land and Water: The Magazine of Natural Resource Management and Restoration. 2004. http://www.landandwater.com/features/vol48no5/vol48no5_2.php .

Dickson, Tom. “Gardens for a Rainy Day.” Minnesota Conservation Volunteer. May-June 2004. http://www.dnr.state.mn.us/volunteer/mayjun04/raingardens.html.

Laberee, Erin. “Implementing Rainwater Gardens in Urban Stormwater Management: Lessons Learned from the City of Maplewood.” November 2004. http://ci.maplewood.mn.us/vertical/Sites/%7BEBA07AA7-C8D5-43B1-A708- 6F4C7A8CC374%7D/uploads/%7B85050727-4FBE-46A1-B29D- D12748E33B83%7D.PDF.

Metropolitan Council, and Barr Engineering. “On-lot Infiltration Systems.” Minnesota Urban Small Sites BMP Manual. ND. http://www.metrocouncil.org/environment/Watershed/BMP/ CH3_STInfilOnLot.pdf.

Middleton, Amy, Sarah Clark, and the Friends of Basset Creek. “Rain Gardens: Gardening with Water Quality in Mind.” March 2007. http://www.mninter.net/~stack/rain/index.htm.

“Native Plants for Raingardens.” Natural Shore Technologies, Inc. ND. www.naturalshore.com.

Nine Mile Creek Watershed District. “2008 Grant / Cost Share Program Guidelines and Summary.” 2008. http://www.ninemilecreek.org/UploadedFiles/39/ 2008%20cost% 20share%20application%20materials%20and%20guidance%20031808.pdf.

"Plants for Rainwater Gardens." Prairie Restorations, Inc. http://prairieresto.com/plants_rainwater.shtml.

“Rain Garden.” Wikipedia: the Free Encyclopedia. 2008. http://en.wikipedia.org/wiki/Rain_garden.

“Retrofitting a Suburban Neighborhood with Rain Gardens.” Water Environment Research Foundation. 2006. http://www.werf.org/livablecommunities/studies_burns_mn.htm.

Rice Creek Watershed District, Blue Thumb Program. "Create a Raingarden." http://www.bluethumb.org/raingardens/.

Schmidt, Rusty, Dan Shaw, and David Dods. Blue Thumb Guide to Raingardens: Design and Installation for Homeowners in the Upper Midwest. 2007. (To order, attend a Metro Blooms workshop or write to raingardens@yahoo.com.)

"2008 Catalog & Cultural Guide: Native Plants and Seeds for Wetland, Prairie, Savanna and Woodland." Prairie Moon Nursery. http://prairiemoon.com/downloads/PMN_2008_Catalog_hr.pdf.

University of Wisconsin—Extension, and the Wisconsin Department of Natural Resources. “Rain Gardens:
A Household Way to Improve Water Quality in Your Community.” 2002. http://clean-water.uwex.edu/pubs/pdf/home.gardens.pdf.

University of Wisconsin—Extension, and the Wisconsin Department of Natural Resources. “Rain Gardens: A How-to Manual for Homeowners.” 2003. http://clean-water.uwex.edu/pubs/pdf/home.rgmanual.pdf.

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