Display Posts by Category

Archives

Rain Gardens

Missouri Botanical Garden Rain Garden
Example of a rain garden, reproduced with permission from the
Missouri Botanical Garden.

What is a rain garden?

A rain garden is a special kind of garden designed to collect and absorb runoff storm water. This would be in an area around your home that may have a slope that after a rain would collect water and hold it for awhile.

Top Ten Reasons for having a Rain Garden

  1. Filter runoff pollution
  2. Conserve water
  3. Protect rivers and streams
  4. Remove standing water in your yard
  5. Reduce mosquito breeding
  6. Increase beneficial insects that eliminate pest insects
  7. Reduce potential of flooding
  8. Create a habitat for butterflies and birds
  9. Survive drought seasons
  10. Recharge local groundwater

Building a rain garden

Find a location

  • Place garden at least 10 feet from your home.
  • Do not place the garden directly over a septic system or near wells or underground utilities.
  • It is better to build the rain garden in full or partial sun, not directly under a big tree.
  • Water should only pool in your rain garden for several hours after the rainfall before it is absorbed.
  • Do not place rain garden in a part of the yard that already ponds. The goal of the rain garden is to encourage infiltration, and those areas have a slow infiltration.

Decide how to channel the water

  • Direct water from downspouts, driveways, patios, or other hard surfaces using gutter extentions, piping, or ditches.
  • If expecting heavy flows of water a rock-lined ditch is advisable.  Line it with landscape fabric to prevent eroding.
  • Stabilize area where water enters the garden with stone to prevent erosion.

Determine size,shape and placement

  • Central portion must be six inches below the grade of the surrounding land in order to temporarily hold water.
  • Gently slope garden: 1 inch drop for every foot across.
  • Rain gardens are best on a flat surface.
  • If on a slope, dig more deeply into the high side of the slope to produce a level bottom.
  • Build a berm or bump on the lower-end to keep water in the garden.
  • Can be circular, kidney-shaped or long and narrow.

Installing

  • Use a garden hose, string, or paint can to delineate the outline.
  • If possible work with dry soil to avoid soil compaction.
  • Loosen the soil at least two feet deep to help plants establish root systems.
  • Use extra soil (3 to 6 inches high) to create a berm along edge of the downslope side. Compact this soil to hold the water in the garden.
  • If soil is mostly clay, amend soil to make it more permeable.
  • Plant your rain garden- work from one side to the other to avoid foot traffic (soil compaction).
  • Water your plants.
  • Mulch your garden.

Choosing the right plants

  • Select plants that can take dry to moist conditions.
  • Try to use native, non-invasive species that are resistant to the stress from both periods of wet and dry.
  • Start with plants that have a good root structure – not from seed.
  • Consider zone hardiness, sun/shade needs, moisture needs, soil type.
  • Choose water loving plants for the lowest portion of the garden (center) and dry-tolerant plants for the edges.
  • Use native plants whenever possible. Native plants will survive better in our environment.

Plant list for a Rain Garden

Trees

  • Red maple, Acer rubrum
  • Serviceberry, Amelanchier canadensis
  • River birch, Betula nigra
  • White ash, Fraxinus americana
  • Green ash, Fraxinus virginiana
  • Witchhazel, Hammamelis virginiana
  • Red cedar, Juniperus virginiana
  • Sweetgum, Liquidambar styraciflua
  • America Hop hornbeam, Ostrya virginiana
  • Pin Oak, Quercus palustris

Shrubs

  • Red chokeberry, Aronia arbutfolia
  • Black Chokeberry, Aronia melanocarpa
  • Inkberry, Ilex glabra
  • American Holly, Ilex opaca
  • Winterberry holly, Ilex verticillata
  • Mountain laurel, Kalmia latifolia
  • Northern spicebush, Lindere benzoin
  • Virginia creeper, Parthenocissus quinquefolia
  • Pinxterbloom azalea, Rhododendron periclymenoides
  • Great Rhododendron, Rhododendron maximum
  • Elderberry, Sambucus canadensis
  • Highbush Blueberry, Vaccinium corymbosium
  • Witherod, Viburnum cassinoides
  • Northern arrowwood, Viburnum dentatum

Perennials

  • Northern maidenhair fern, Adiantum pedatum
  • Jack-in-the-pulpit, Arisaema triophyllum
  • Wild Columbine, Aquilegia canadensis
  • Bushy Aster, Aster dumosus
  • New England Aster, Aster novae-angliae
  • Glade fern, Deparia acrostichoides
  • Sweet Joe-Pye weed, Eupatorium purpureum
  • Wintergreen, Gaultheria procumbens
  • Wild Geranium, Geranium maculatum
  • Cardinal flower, Lobelia cardenalis
  • Great blue lobelia, Lobelia siphilitica
  • Bee balm, Monarda didyma
  • Interrupted Fern, Osmunda claytoniana
  • Switchgrass, Panicum virgatum
  • White-beard tongue, Penstemon digitalis
  • Silverleaf mountain mint, Pycnanthemum incanum
  • Wrinkled-leaved goldenrod, Solidago rugosa
  • New York fern, Thelypteris noveboracensis

For more information about rain gardens (also known as wetlands), visit the Backyard Conservation website of the US Department of Agriculture.

Comments are closed.