A rain garden is a depression about 15 centimetres (6 inches) deep. It catches water from a downspout, or driveway and spreads it through the garden so it soaks into the ground rather than running on to hard surfaces or into a storm drain.
The garden should be as level as possible so water does not pool or spill out of the garden
Water should soak into the ground within 24 hours for ideal plant conditions.
Sandy soils absorb water the fastest, while clay soils absorb the slowest. If you have clay soil, your garden will need to be larger.
Add 5 centimetres (2 inches) of organic material (e.g. manure, compost, leaf mold) every two years to create rich, nutritious soil, and remove the need to fertilize.
For the first few weeks, keep the top 2.5 centimetres (1 inch) of soil moist. After that, water once a week until plants are established (one to two seasons).
Adding 5 to 10 centimetres (2 to 4 inches) of mulch every few years to reduce watering needs, prevent weeds and increase plant survival and growth.
Rain garden design—full sun
At least six hours of direct sun a day
Rain garden plants—full sun
Spring interest
- Amsonia species, blue star
- Baptisia alba, white false indigo
- Geum triflorum, prairie smoke
- Lobelia cardinalis, cardinal flower
Summer interest
- Asclepias incarnata, swamp milkweed
- Eupatorium species, Joe Pye weed
- Liatris aspera, blazing star
- Sisyrinchium species, blue-eyed grass
Fall interest
- Carex grayi. morning star sedge
- Chelone glabra, white turtlehead
- Oligoneuron ohioense, Ohio goldenrod
- Symphyotrichum laeve, smooth blue aster