Rain gardens catch runoff from parking areas,
driveways, walkways and roofs, allowing stormwater to
slowly filter into the soil rather than flow directly
into storm drains, ponds or lakes. This allows
30% more water to soak into the ground and recharge
our underground water supplies. It also reduces
the amount of polluted runoff entering our waterways.
The
NepRWA Rain Garden was designed to be a functional
infiltration system that would also educate people
about how to return rainwater to the
groundwater system.
We hope
that you will consider creating a rain garden in your
own yard! Below
is a list of the plants that we used in the NepRWA
rain garden, as well as information about soil
amendments. You will also find steps toward
building your own rain garden.
How
to Build A Rain Garden:
Location:
Find a lawn area with a slope between 1% and 10% that
is more than 10 feet away from any building
foundations. You may have to re-direct a
down-spout towards your garden to ensure that your
plants will receive sufficient water.
The downspout should end four feet from the outside edge
of the garden.
Size:
The garden should be 1/3 the size of the surface
area providing the runoff.
Depth:
Make a depression 6 to 18 inches
deep, throughout the area of the garden.
Plants:
Ideally, plant at least 15 species
of plants at a density of 1 plant per square foot. As
the rain garden matures, thin the
population of some of the plants to allow others to
grow. When planting, put the tallest flowers and
shrubs in the deepest part of the swale. For
information on specific plant and shrub options for
your soil and weather conditions, visit www.mninter.net/%7estack/rain
Maintenance:
In the weeks following planting, you may want to hoe
dandelions and other weeds until the mature garden
plants crowd them out. Also, during the first year,
your rain garden will require monthly weeding during
the growing season. In subsequent years, it will
only be necessary to weed once per year. Shrubs
should be pruned annually. During extremely dry
periods it may also be necessary to water several
times per week.
TIPS:
The addition of peat moss or compost increases the
soil's ability to hold water.
In case of a large rain storm, it is important to
provide a way for excess water to drain out of the garden in order to prevent flooding
of your garden.
To increase the number of songbirds and butterflies
present, incorporate berry- and nectar-producing plants.
Leave the dead or dormant plants standing over the
winter. Many of these plants will provide seeds and shelter for
birds. In the spring, cut-back or mow the plant stalks to allow new shoots to emerge.
Herbaceous
Plant List:
Osmunda regalis, Royal
fern
Adiantum pedatum, Maidenhair fern
Lobelia cardinalis, Cardinal flower
Tiarella cordifolia, Foamflower
Dicentra eximia, Fringed bleeding heart
Polygonatum falcatum, Dwarf Solomon's seal
Asclepias tuberosa, Butterfly weed
Aquilegia canadensis, Columbine
Panicum virgatum, Switchgrass
Matteuccia struthiopteris, Ostrich fern
Woody Plant List:
Clethra
alnifolia, Summersweet clethra
Cornus sericea (stolonifera), Red-osier
dogwood
Vaccinium corymbosum, Highbush
blueberry
Ilex glabra 'Compacta,' Compact inkberry
holly
Ilex verticilatta,
Winterberry (various types, incl. Red sprite)
Leucothoe
fontanesiana, Drooping leucothoe
Soil
Amendments:
NepRWA used a mixture of topsoil,
farm compost and lightweight stone aggregate
in the garden to promote root
growth and infiltration of water. In this way, most rainwater runoff
will recharge the local groundwater and nourish the
rain garden's root system. This mixture also
ensures that the soil in the rain garden holds water for no longer than 72
hours.
For
more information:
Rain
Gardens 'Cut City Pollution' (BBC, 2006)
Rain
Gardens by Karen Cozzetto. Conscious Choice, May 2001
Rain
Gardens: Gardening with Water Quality in Mind
Learn
more about maintaining
your yard in
an ecologically-friendly way. See this,
too.
