The Beneficial Beauty of Rain Gardens

The photo below is one of the most inspiring rain garden images I’ve seen … what if all streets were lined with rain gardens? Think of the benefit to water quality and life. What if rain gardens were as common as lawns?

Rain gardens are designed to capture rain water and prevent the rapid release of excess stormwater into municipal water systems. A well placed rain garden reduces runoff and flooding, and filters pollutants carried in stormwater runoff. Along with the municipal benefits and the conservation of a valuable natural resource, rain gardens create excellent habitat for birds and butterflies. Amazing. So why aren’t they as common as lawns?

First, lets look at some basic misconceptions…

  • Misconception #1: Standing water in rain gardens can breed mosquitoes.
    Rain gardens are designed to drain in less than 24 to 48 hours – not enough time to create a mosquito breeding environment. Rain gardens in areas with better soil drainage will drain even faster – down to 12 hours.

  • Misconception #2: Only plants that require wet growing conditions will thrive in a rain garden.
    A rain garden is not a pond. It is dry most of the time. A variety of plants that tolerate a wide range of conditions work best. Plants located in the lower part of a rain garden may stand in water on occasion, but they must also tolerate long periods of drought. Plants on the sides of the garden will vary between occasionally wet soil and dry conditions. Plants at the highest points may never experience standing water.

  • Misconception #3: Rain gardens look wild and weedy.

    Gardens look weedy when: plants grow too tall and flop over; too many plant varieties are used; plants are not in distinct groups; or gardens don’t have defined edges. By using plants in scale with the garden size, placing taller plants in the middle of the garden, maintaining well-defined edges, and creating attractive plant groups, rain gardens can make beautiful additions to a landscape. (see photo, above)

Why do we need rain gardens?

As urban communities expand (replacing forests and agricultural land) the increase of solid impervious surfaces becomes more problematic. The solid surfaces that make up our cities create a rush of water during rain storms, known as ‘stormwater runoff.’ The massive volume of stormwater runoff from roofs, parking lots and roads increases flooding and carries pollutants from streets, parking lots and lawns into local streams and lakes. This leads to costly municipal improvements in stormwater treatment structures.

With larger or more frequent storms, increased water flows can contain more water than a municipal water system can handle. In some municipalities, excess unfiltered stormwater (overflow) that can’t be dealt with is let directly into lakes. Large stormwater flows also carry debris, clogging storm sewer exits and contributing to flooding. Refuse that runs with the storm water will also pollute the end catch basin, whether a drainage ditch or trout stream. Lawn pesticides and fertilizers wash off with the rain water, causing nutrient loading, decreased oxygen levels and subsequent algal blooms within our local lakes and rivers. Decreased oxygen levels have proven to produce declines in fish populations and overall decreases in aquatic species diversity.

A rain garden is a personal contribution to clean water in your community

To reduce stormwater runoff from your property look at your property and identify where the water goes. A rain garden should be positioned near a runoff source like a downspout, driveway or sump pump to capture rainwater runoff and stop the water from reaching the sewer system.

An individual rain garden may seem like a small thing, but collectively they produce substantial neighborhood and community environmental benefits. Rain gardens improve water quality – they can reduce the amount of pollution reaching creeks and streams by up to 30%.

Resources to get started

The construction of a rain garden is a task that an average homeowner can undertake with a bit of guidance. Good sources of information on rain gardens is available through a Wisconsin DNR and UW Extension publication developed by Roger Bannerman:  Rain Gardens: A how-to manual for homeowners (PDF).

One of the keys to a successful rain garden is chosing plants that not only soak up excess water, but are also drought and heat tolerant. Midwestern plants that grow in clay soils fit that criteria. Read Neil Diboll’s list of plants for Midwestern rain gardens on clay soils (PDF).

Prairie Nursery offers a selection of pre-planned rain gardens in various sizes and for various soil conditions. Gardens come with planting instructions and layout.

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Benefits of a Rain Garden

• Filter runoff pollution
• Recharge local groundwater
• Improve water quality
• Protect streams and lakes from pollutants carried by
urban stormwater – lawn fertilizers and pesticides, oil and
other fluids that leak from cars, and numerous
harmful substances that wash off roofs and
paved areas
• Remove standing water in your yard
• Reduce mosquito breeding
• Protect communities from flooding and drainage problems
• Create habitat for birds, butterflies and beneficial insects
• Create drought tolerant green areas
• Enhance the beauty of yards, neighborhoods and parks

 

 

Featured Plant:
Red Milkweed (Asclepias incarnata)


In recognition of Earth Day 2013, Prairie Nursery is donating 5% of sales of Red Milkweed and other select Monarch favorites to Monarch Watch, a nonprofit education, conservation, and research program based at the University of Kansas that focuses on the monarch butterfly, its habitat, and its spectacular fall migration.


In its native environment Red Milkweed (AKA: Swamp Milkweed, Marsh Milkweed, Rose Milkweed) is found growing in floodplains, wet meadows, and near the edges of ponds, lakes and streams.  It also grows very well in average, well-drained garden soil. We have a huge specimen, here at the Prairie Nursery farm, that has flourished on a pretty dry site. Full sun is best and some light shade is tolerated.

Red Milkweed plants form a stately bunch of upright stems with long narrow leaves and heads of fragrant mauve-pink flower clusters, composed of many small intricate blooms. At 3′ – 5′ tall a single large clump of Red milkweed makes an excellent focal point in a garden. Put to good use in rain gardens, this Asclepias is also used in shoreline restoration, shoreline buffers, detention basin and bio-swales.

The flowers of Asclepias incarnata are attractive to all kinds of butterflies. The female Monarch Butterfly lays eggs, exclusively, on plants in the Asclepias family, and Red Milkweed is known to be one of the best attractors. Monarchs feed on the flowers and lay their eggs on the plants. The emerging caterpillars then feed on the leaves.

Below is a photo taken at a friends vegetable garden, with Red Milkweed growing among the Asparagus.

The seed pods are a beautiful accent in the fall landscape with their slender pointy shapes and a red/pink tinge. Below is a fall display of Red Milkweed pods, Showy Goldenrod and Sideoats Grama grass.

Red Milkweed occurs naturally throughout most of the U.S., and much of Canada.

Native Plants that Grow Under Pines

The plants listed in today’s post are great choices for planting under most deciduous trees, and all are tolerant of the acid environment under conifers (pine, spruce, fir, etc.). The rhizomatous species work well as groundcover. (Scroll to end of article to see images of Bearberry in sandy conditions under pines.)

Planting Tips:

  1. Keep in mind the mature heights of plants as well as their mature width. The height of the tree and the height of its lowest branches will influence how tall the under-planting should be.
  2. Care should be taken to minimize disturbance and damage to tree roots during the preparation and planting processes. It is best to avoid large power equipment. There is a common misconception that most tree roots are deep and create a mirror image of the tree’s crown. In reality, most roots are fairly close to the surface and reach even beyond the drip-line.
  3. In an effort to disturb tree roots as little as possible, plant small-size container plants (2-1/2″ to 4″ pots), even if they will grow to a much bigger mature size. Remember to space plants allowing for their mature size.
  4. It is a good idea to mulch your transplants, especially when newly planted. The new small plants are sharing the available moisture with a large tree. Mulch will help to retain valuable water. In a woodland environment plants benefit from the cover of leaves and pine needles.

Flowering Herbacious Plants

Scientific Name Common Name Height Soil Moiture Notes
Arctostaphylos uva-ursi Bearberry 6″ – 1′ Dry-medium Rhizomatous; Deer resistant
Asarum canadense Wild Ginger 1’ Dry-medium Rhizomatous
Aquilegia canadensis Columbine 2-4’ Dry-medium Deer resistant, hummingbirds
Aster divaricatus White Woodland Aster 2-4’ Dry-medium Rhizomatous
Aster cordifolius Heart Leaved Aster 2-3’ Dry-medium Rhizomatous
Cornus canadensis Bunchberry 6″ 1’ Dry-moist Rhizomatous, Deer resistant
Gaultheria procumbens Wintergreen 6″-1′ Dry-moist Rhizomatous
Geranium maculatum Wild Geranium  1-2’ Dry-medium Rhizomatous
Heuchera Americana American Alum Root 1-3’ Dry-medium
Helianthus strumosus Woodland Sunflower 3-5’ Dry-medium Rhizomatous, Bird, Deer resistant
Podophyllum peltatum Mayapple 1-2’ Dry-medium Rhizomatous. Foliage dies back in late summer.
Polemonium reptans Jacob’s Ladder  1-2’ Medium Excellent texured foliage.
Smilacina racemosa Solomon’s Plume 1-3’ Medium Rhizomatous
Smilacina stellata Starry Solomon’s Plume 1-2’ Dry-medium Rhizomatous
Solidago flexicaulis Zigzag Goldenrod 2-4’ Dry-medium Rhizomatous
Solidago odora Anise Scented Goldenrod 1-2’  Dry-medium
Uvularia grandiflora Bellwort  1-2’ Dry-medium Spring Ephemeral.

Ferns

Scientific Name Common Name Height Soil Moiture Notes
Adiantum pedatum Maidenhair Fern 1′ Dry-medium Rhizomatous; Deer resistant
Athyrium felix-femina Lady Fern 1’-2′ Dry-medium Rhizomatous; Deer resistant
Gymnocarpium Dryopteris Oak Fern 6″-1’ Dry-medium Rhizomatous; Deer resistant
Osmunda regalis Royal Fern 3′-6′ Moist Rhizomatous; Deer resistant

Sedges

Scientific Name Common Name Height Soil Moiture Notes
Carex eburnea Ivory Sedge 4”’-11″ Dry-medium Deer resistant
Carex pensylvanica Pennsylvania Sedge 1’ Dry-medium Rhizomatous; Deer resistant

 


Bearberry, growing under pines and among the juniper
along the Lake Michigan shoreline:

Bearberry along the Lake Michigan shoreline.