As greener living grows more popular, so does interest in environmentally friendly practices for the home landscape. Instead of removing excess water from your property, try a rain garden. This specialized garden creates an engaging natural area that will attract birds and butterflies while also improving local water quality.
A rain garden is a natural or man-made depression that collects excess rainwater runoff from rooftops, roads, parking areas or compacted lawns. The depression is planted with shrubs and perennials that tolerate pooling water as well as periods of drought. These plants absorb and filter the water before it percolates into the soil, thus reducing storm water runoff and protecting water resources.
In our area, an average rain storm can produce 2 inches of rain in a 24-hour period. Even 2 inches of rain falling on the roof can result in more than 600 gallons of water rushing through downspouts. As rain travels over hard surfaces, it picks up and carries pollutants such as oil, pesticides, fertilizers and animal waste. Because much of the natural vegetation has been removed and replaced with impervious surfaces, the rain water does not infiltrate into the soil. Instead, it flows to the storm sewer and into local streams, which are often unable to handle the higher volumes, causing back up and eventual flooding.
Here are some dos and don'ts of establishing a rain garden:
• Locate it at least 10 feet from the building so that infiltrating water does not seep into the foundation.
• Do not install a rain garden over a septic system, near walls or near underground utilities.
• Select a site that is in full sun or partial shade, and avoid areas under large shade trees.
• Do not fertilize plants that are growing in the rain garden.
• Do not site one in an area where water currently pools; this is a sign that infiltration is slow. Rain gardens should be placed in areas where water infiltration is good.
• An established rain garden should not pool for more than six hours after a rain storm due to possible mosquito and plant issues.
Certain plants will thrive in a rain garden. This list will help you get started:
- Serviceberry (Amelanchier spp.)
- Black chokeberry (Aronia melancarpa)
- Pawpaw (Asimina triloba)
- Buttonbush (Cephalantus occidentalis)
- Sweet pepperbush (Clethra alnifolia)
- Shrub dogwood (Cornus sericea)
- Bush honeysuckle (Diervilla lonicera)
- Inkberry (Ilex glabra)
- Winterberry holly (Ilex verticillata)
- Spicebush (Lindera benzoin)
- Northern bayberry (Myrica pensylvanica)
- Arrowwood viburnum (Viburnum dentatum)
- Swamp milkweed (Ascelpias incarnata)
- Turtlehead (Chelone glabra)
- Joe pye weed (Eupatorium maculatum)
- Cardinal flower (Lobelia cardinalis)
- Blue lobelia (Lobelia siphilitica)
- Virginia bluebells (Mertensia virginica)
- Ironweed (Vernonia noveboracensis)
- Lady fern (Athyrium filix-femina)
- Royal fern (Osmunda regalis)
- Cinnamon fern (Osmunda cinnamomea)
- Tussock sedge (Carex stipata)
Several area nonprofit organizations and green industry professionals have joined efforts to promote the installation of rain gardens as a means of reducing storm water impact in the region. The group, called Three Rivers Rain Garden Alliance, will kick off its efforts with its first rain garden installation at Phipps' May Market: An Eco-Garden Fair, May 16-18 in Mellon Park. Representatives from the participating organizations will be available throughout the fair to share their expertise on installation, plant selection and maintenance.
This is one of a series of periodic columns by staffers of Phipps Conservatory and Botanical Gardens. Nancy Knauss is an adult education coordinator.