Adams
County Soil & Water Conservation District
338
South 36th Street Quincy, IL 62301 Phone:
217/224-9305, Ext 3 E-mail:
acsw@adams.net
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What is a Rain Garden?
A rain garden is a shallow depression in your yard that is planted with native flowering plants and grasses. The garden not only looks nice, but soaks up rain water and melted snow from your roof gutters, driveway or lawn. Holding back this runoff helps prevent pollutants such as fertilizers from washing off your yard into storm sewers and eventually into nearby streams. The water that is soaked up by your rain garden also reduces the chances of local flooding.
Before building a rain garden, there are some basic questions
to answer.. They are: Your home rain garden can be either near the house to catch only
roof runoff, or farther from the house to catch both roof runoff and lawn
runoff. To help you decide, consider the following:
A typical home rain garden ranges from 100 to 300 square feet in size. A general rule of thumb is to make your rain garden 1/3 the size of the area draining into it. For example, if you are locating the garden to catch just roof runoff, and your roof area is 50 feet long by 30 feet wide (1500 square feet), then your garden area should be 1500 square feet in size (15' x 10'). The depth should be 4 - 6" deep. If you have sandy soils, the garden can be smaller; for clay soils, it should be larger. For more detailed information on sizing, visit www.raingardennetwork.com Rain gardens can be any shape. Choose one that fits your landscape. Ovals or unusual shapes add more appeal to the landscape. You can use a rope to lay out possible shapes and designs to see which one you like best. Remember - before digging the rain garden, call JULIE at 1-800-892-0123 to be sure there are no underground utilities. In order to choose the plants you want for your garden, you must know: Once you have this information, you can choose plants that are adapted to your soil and site conditions. Take into consideration the mature height of the plants, the bloom time and color, and the shape and texture of the plant. Mix heights, shapes, color and bloom time so that the garden is interesting throughout the year. It is also a good idea to "group" plants, with 5 - 7 plants of the same species planted close together. Do this in a random pattern, repeated throughout the garden. Examples of rain garden designs and native plant species can be seen at the University of Wisconsin Extension Service's Clean Water web page. The cost of a rain garden will vary, depending on whether you do the work yourself or hire someone to do it. Native plants are relatively expensive, but using plants is much better than seed. Plugs are available from many nurseries, and are a less expensive alternative than larger plants - and plugs will bloom the first year of planting. You should plant in late spring/early summer for the best results. Once your garden is built and planted, maintenance will be minimal. Mulch and water every other day for the first two weeks or so until your plants get established. Weed as necessary. Leave the vegetation over the winter - it will provide cover and food for the birds and wildlife. In the spring, cut off the dead vegetation. Additional weeding may be required in the first two years. In later years, as the plants mature, some thinning may be needed. One rain garden concern is that the standing water will become a breeding grounds for mosquitoes. While rain gardens do pool water for a short period of time, the garden is dry between rainfall events. Mosquitoes need 7 - 12 days to lay and hatch eggs, and the standing water will last only for a few hours after most storms. Also, rain gardens attract dragonflies, which eat mosquitoes. Adams County Rain Garden Projects The Illinois Environmental Protection Agency, through the Association of Illinois Soil and Water Conservation Districts, provided funding to develop a bio-retention structure on the Quincy campus of John Wood Community College. This is a BIG rain garden. Over 3000 native plants (adapted to wet soil conditions and full sun) were planted in June of 2006. After much watering during the extremely dry summer months, most of the plants mysteriously disappeared. It was determined that a flock of geese arrived in early August, and consumed some the plants. Early summer of 2007 showed that some of the plant roots survived, and soft-stemmed bulrush, fox sedge, blue flag iris, and arrowhead were emerging. In June, 2007, over 1000 native plants were planted, consisting of blue flag iris, swamp milkweed, cardinal flower and New England aster. The John Wood Community College Environmental Geology class, along with instructor Gary Shupe planted and installed goose netting.
Planting Day at JWCC The Unity High School FFA Chapter applied for and received a grant from Lieutenant Governor Pat Quinn for a rain garden on school property. This was planted in early June, and watered throughout the dry summer by Chapter members.
Site of rain garden - note roof downspouts in background |
