Q. I would like to install a rain garden. What are the first steps?
If you have an area of your garden in which water collects after a rain storm then you can quite easily make a rain garden without too much excavation..Or you may want to build a rain garden to divert the gutter water from your roof so that it doesn't run into the street and into municipal sewer. A rain garden is an ecologically and environmentally-sound project.
A rain garden can be any size consistent with the size of your garden or the amount of gutter rain that you wish to divert. An area of 150 sq ft. will make an impressive garden. It should be located at least 10ft. away from your house and not over a septic tank.Strip away any lawn before beginning the project. An ideal depth is 4 - 10 inches. Any excavated soil can be used to create a bern at the lower end of the garden to hold the water in. It may be a good idea to install an overflow pipe to carry excess water to the street or another location in the garden. Add a layer of compost before planting the garden and mulch around plants when they have been installed.
Unless your rain garden is permanently water-logged it is not advisable to plant it with water-loving or aquatic plants. Plants labeled "for average to moist conditions" are most suitable. Choose native plants where possible as they will survive best.
Some areas of the garden will be wetter than others so chose your plants accordingly. Sedges. reeds, and many ferns (e..g Lady fern (Athyrium filix-femina) will do well in wetter areas. Otherwise asters, daylilies, and coneflowers are good choices. Irises are often planted in rain gardens. To vary the height of your plantings large herbaceous plants such as Joe-pye weed (Eupatorium fistilosum) can be incorporated.. Shrubs, such as sweet pepper bush (Clethra alnifolia) can also be used.
For more detailed instructions on building a rain garden you can refer to our guide Rain Gardens and there are several web-sites that can be consulted e. g.:
This book: Rain Gardens N. Dunnett and A. Clayden Timber Press, Portland, OR (2007) is a useful guide. It covers mainly large scale projects but there is a section on "Designing Your Rain Garden".and a useful list of suitable plants.
Courtesy of NYBG Plant Information