Rain Gardens

What is a Raingarden? 
Raingardens look like regular flower gardens, but they are so much more. Raingardens are a sustainable infrastructure and are typically planted with deep-rooted native plants and can be colorful, landscaped areas in your yard that will also provide important environmental benefits. When it rains, a raingarden fills with a few inches of water and allows that water to slowly filter into the ground rather than running off to storm drains that connect to surface water (streams and bays) and groundwater (drinking water source). They are gardens designed to soak up rain, compared to a same size patch of lawn raingardens allow about 75% more water to soak into the ground! They also provide wildlife habitat and add beauty to neighborhoods!

 

The Benefits of Raingardens

  • Increase the amount of water that filters into the ground, which recharges aquifers 
  • Help protect against flooding and drainage problems 
  • Remove standing water in your yard 
  • Help protect streams and lakes from pollutants carried by stormwater—fertilizer, car fluids, salt & pesticides 
  • Improves water quality through the removal of pollutants 
  • Create habitats for birds, butterflies, dragonflies and many beneficial insects 
  • Native plants flower in a variety of colors throughout the summer months, creating a garden that is equally beautiful and beneficial 

 

Please feel free to post and of your raingarden pictures to our Facebook page, tag them with #PlantingforCleanWater

    Purple Coneflower – Echinacea purpurea 

    Golden Alexander – Zizia aurea Coneflower

    Blazing Star – Liatris spicata 

    Plan: Choosing a spot
    Raingardens can be designed to catch water from a roof or driveway. Pick a sloped spot with a slight depression; you’ll have less digging to do.
    It is important to remember that raingardens:

    • Are not a solution to constant wet areas!

    • Must have good drainage so that the water can soak in within 24 hours after a rainfall. This will detract mosquitoes.

    • Should be at least 10 feet away from a building to prevent seepage into the building. Use a gutter lead or build a swale to direct rainwater from roof or driveway to raingarden.

    • Should not be built over a septic system.

    • Must include an overflow outlet to transport excess rain to a proper location (not your neighbor’s lawn!).


    Prepare: How Big?
    Size of raingarden will depend upon 3 key factors:

    1. Size of drainage area (A typical residential raingarden is about 50-100 square feet)

    2. Type of soils on site

    3. Depth of raingarden 

     

    For advice on calculating dimensions of raingarden or testing soil contact the Nassau County Soil and Water Conservation District at

    516-364-5860 or email us at nassauswcd@optonline.net

     

    Ready to Dig?

    • Before digging, call Dig Safe NY at 1-800-272-4480 to detect underground utility lines!

    • Use string to outline shape of raingarden.

    • More digging will be required on uphill side.

    • Use an extra soil to build a berm on downhill side, so soil will be carted away.

    • Bottom of raingarden must be flat and level.

    • Make an overflow outlet for heavy rain events.

     

    Dry Zone Native Plants 

    • Purple Coneflower – Echinacea purpurea 
    • New York Aster – Symphyotrichum novi-belgii 
    • Butterfly Weed – Asclepias tuberosa 
    • Seaside Goldenrod – Solidago sempervirens 
    • Little Blue Stem – Schizachyrium scoparium 

      Wet Zone Native Plants 

      • Inkberry – Ilex glabra 
      • Swamp Milkweed – Asclepias incarnata 
      • Blue Flag Iris – Iris versicolor 
      • Golden Alexander – Zizia aurea 
      • Blazing Star – Liatris spicata

      Plant Selection              

      Choose plants that:

      • Have a variety of heights, textures, and bloom times.
      • Native perennial plants are the best. It is critical to select “dry” plants that can tolerate infrequent heavy “wet” conditions like a major storm, and that are suited to sun or shade exposure of raingarden.

       

      Tip: Dig each hole twice the width of plant root-ball. The hole should be deep enough so that top of plant’s root-ball is level with ground.

      Why Native Plants in Your Raingarden? 

      The plants that do well in raingardens are the ones that can tolerate wet conditions, but also very dry conditions.  Many plants native to New York fit this description. Native plants have long, water-soaking roots that help the water infiltrate into the ground. 

      New York Aster – Symphyotrichum novi-belgii