RAIN GARDENS

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RAIN GARDENS

• These educational materials are
• the courtesy of
• http//www.raingardens.org
• http//www.rainkc.com
• Compiled here by Liz Hugel / GINLC Education
  Committee

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What is a rain garden?

• A rain garden is an attractive landscaping
  feature planted with perennial native plants. It
  is a bowl-shaped garden, designed to absorb
  stormwater run-off from impervious surfaces such
  as roofs and parking lots.
• Rain gardens can be small, formal, home-owner
  style gardens, large complex bioretention
  gardens, or anywhere in between.

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Why do we need rain gardens?

• Rain is natural stormwater isn't. Government
  studies have shown that up to 70 of the
  pollution in our streams, rivers and lakes is
  carried there by stormwater. Although most people
  never think about stormwater, about half of the
  pollution that stormwater carries comes from
  things we do in our yards and gardens!
• Planting a rain garden may seem like a small
  thing, but if you calculate the amount of rain
  that runs off your roof, you would be very
  surprised. That rain is supposed to soak into the
  ground, but instead heads down the street to the
  storm drain, carrying pollution with it.
• Keeping rain where it falls, by putting it into a
  beautiful rain garden, is a natural solution. You
  not only get a lovely garden out of it, you have
  the added benefit of helping protect our rivers,
  streams and lakes from stormwater pollution. You
  can be part of a beautiful solution!

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What Makes a Garden a Rain Garden?

• A rain garden resembles a regular perennial
  garden in many ways.
• It is designed with deep-rooted plants that come
  back year after year it is pretty to look at it
  often has lovely flowers, grasses, trees and
  shrubs.

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Qualities that make a rain garden unique.

• Rain Gardens have a ponding area, but they are
  not ponds. They often are planted with wetland
  plants, but they are not wetlands (although you
  can design a rain garden that mimics a wetland).
• The garden absorbs and filters rain that would
  otherwise run off your property and down the
  storm drain. This stormwater runoff usually comes
  from an impervious surface that rain cannot soak
  into, such as a roof or parking lot, or even a
  lawn.
• Many of the plants in the garden are native to
  the region, and have extensive deep roots that
  help the garden absorb rain. The native plants do
  not need special attention once they are
  established.
• There is a bowl-shaped dip in the garden, which
  holds the rain while it soaks into the soil.
• The garden bed is prepared or sometimes replaced
  to a depth of two feet in order to de-compact the
  soils and make the garden able to absorb water.

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Benefits of Rain Gardens

• Rain gardens are lovely landscaping features.
• Rain garden plants create wildlife habitat and
  attract butterflies, birds, and other wildlife.
• Rain gardens can save you money. They don't need
  to be fertilized or sprayed, only weeded and
  mulched. They reduce the amount of lawn you have
  to maintain. This makes your yard a healthier
  place for children and pets.
• A rain garden on your property makes you part of
  a solution to stormwater pollution. Rain gardens
  can potentially absorb hundreds of gallons of
  rain that would otherwise wash pollution down the
  street and into the nearest river, stream, or
  lake. Even small rain gardens can absorb a lot of
  rain.
• A rain garden can be part of a stormwater
  reduction plan to help solve problems of combined
  sewer overflows (CSOs).

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Benefits of Rain Gardens cont

• Rain gardens can actually remove many of the
  common pollutants in stormwater. (fertilizers,
  pesticides, oil residue )
• Rain gardens are low maintenance. Once
  established, they require no fertilizer,
  watering, or mowing. A once a year cleanup,
  addition of shredded hardwood mulch to keep the
  surface moist and tidy, and removal of weeds and
  invasive species are all that are required.
• Rain gardens can contribute to groundwater
  recharge, a natural process that is interrupted
  by soil compaction and hard surfaces created
  during development and building.
• A rain garden project can educate the public
  about the problems that stormwater runoff
  creates, while giving people a beautiful
  solution.
• A rain garden project can be part of the
  educational toolbox used by a community
  stormwater education team.

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Benefits of Rain Gardens cont

• Reduce mowing
• Lawn mowing contributes greatly to the ozone
  problem. Engines are inefficient at reducing
  pollution. In fact, using a gasoline-powered lawn
  mower for one hour generates the same amount of
  air pollution as driving a car for forty hours. A
  gasoline-powered weed eater operated for one hour
  is even worse as it generates pollution
  equivalent to driving a car for sixty hours.

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How much does it cost to build a rain garden?

• Rain gardens cost no more than regular flower
  gardens.
• The cost elements are the flowers, the peat moss
  or compost that you add to the garden, plus any
  edging or walls that you might build.
• Flower costs are a function of the size and
  number of flowers that you choose.
• A do-it-yourself homeowner who starts with mostly
  smaller plants might spend 2 to 4 per square
  foot.

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Before Starting Choose The Right Place for Your
Rain Garden

• A rain garden is one type of bioretentiona
  system of pond area, soil, plants and mulch that
  will retain water and soak it up instead of
  letting it run off of your property (even though
  your pond will be dry most of the time).  So
  the most basic things are the pond, or
  depression into which water will flow, and the
  soils that will absorb the water.
• Your property has an existing drainage pattern
  (even though it may not be very noticeable), and
  it will usually be easiest to take advantage of
  that. Note the direction of runoff and low spots
  where water collects.

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Hints for choosing a spot

• Avoid creating a rain garden too close to
  building foundations this may lead to a leaky
  basement.
• Be aware of rights of way and underground service
  lines or utilities.
• Re-directing the rain--there are a number of
  creative and attractive solutions if the rain
  doesnt flow naturally to your chosen spot.
• If your land slopes, you can create a flat area
  for your rain garden in several ways.
• Black walnut trees growing by the garden may
  spell trouble, due to juglone, a chemical exuded
  from their roots.
• Dont excavate an extensive rain garden under
  large trees.

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Evaluate the Soil

• Soils vary greatly in fertility, drainage, and
  pH rating.  Understand what kind of soils you
  are working with, and put in a garden suitable to
  the conditions you already have.
• Drainage is important
• Test your drainage!
• Design the Pond.
• Compacted Soils
• pH and Other Qualities

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Prepare the Site

• Define the Borders
• How much soil is needed for replacement?
• Improve the Soil
• Grading the pond area

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Develop a Design

• Tall Great Lakes Prairie Rain Garden For Sun (6
  hours of sunlight) and clay soils.
•  
• Short Great Lakes Prairie Rain Garden For Sun (6
  hours of sunlight) and clay soils.
•  
• Maplewood, Minnesota rain garden designs
• University of Wisconsin Extension Rain Garden
  Manual.

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Select the Plants Use native plants in rain
gardens

• Native plants can tough it out
• Native plants attract beautiful creatures
• Native plants have deep roots
• Obtain native plants
• Do not take your plants from the wild.
• Plan Ahead for Plant Needs

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Plant the Garden Rain Garden Care

• If it doesn't rain, water your plants until they
  are established.
• Break strong water flow.
• Mulch your rain garden.
• Weed regularly.
• Don't park or drive on your rain garden. 
• Don't let sediment, soil, sand, or debris flow
  into your rain garden.
• Keep an eye on the plants.

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Rain Barrels

• Saving Rain for a Sunny Day
• During a typical moderate storm of 1 of rain
  during a 24 hour period, over 700 gallons of
  water will run off the average roof, an
  impervious area of about 1,200 square feet. 
• In one rainy day, your roof runoff could fill up
  fourteen bathtubs!

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Rain Barrels

• Your barrel must be made of food quality
  materials, so the water you save will remain
  uncontaminated. 
• 2) Your rain barrel should NOT have a lid that
  easily comes off. This will insure that little
  creatures and little people will not be at risk
  of drowning in your rain barrel.
• 3) Your barrel should be safely screened so it
  doesnt turn into a mosquito condo.