Design
     RainGardens

RainGardens are the hottest new thing in water gardening because of renewed concerns for the environment. They are landscaped areas planted with native wild flowers and other cultivated wetland plants that soak up rain water, mainly from roof water downspouts. A RainGarden fills up with a few inches of water after a storm and then slowly filters the water back into the ground rather than running off into your local storm sewer system.  Alternatively, a Water Retention RainGarden can capture the same storm water into a filtered underground reservoir so you can use it to irrigate your landscape at a later date during dry periods.

Why are rain gardens important? As development and urban expansion replaces agricultural land and forests, increased storm water runoff from impervious surfaces becomes a big problem for residents in municipalities across Canada . Excessive runoff increases flooding; carries pollutants from streets, parking lots and even lawns into local streams and lakes; and leads to costly municipal improvements in local storm water management infrastructures.

While an individual RainGarden may represent only one small part of the solution, collectively they can produce substantial environmental benefits for your neighbourhood and community.

RainGardens will benefit you in several ways by:

Increasing the amount of water that filters into the ground, thereby
    recharging local and regional aquifers.

Allowing you to get rid of unsightly, inefficient rain barrels. Water
    Retention RainGardens allow you to store storm water
    underground and out of sight.

Preventing flooding and drainage problems in your
    neighbourhood and your surrounding community.

Helping protect streams, rivers and lakes from pollutants carried
    by urban storm water- lawn fertilizers, pesticides, oil and fluids
    from roads and vehicles, fecal matter from pets and farm stock,
    and other harmful substances from rooftops and paved areas.

Enhancing the beauty of your yard and garden.

Providing valuable habitat for native birds, butterflies and
    beneficial insects.

Does a RainGarden form a pond?

No. The rain water will soak in so your RainGarden is dry between rainfalls. If you wish to have the sights and sounds of water in your landscape you can install a Water Retention RainGarden, where water is stored in a storage basin beneath the planting beds. By adding a bubbling urn or a decorative spitter feature, you can create a beautiful re-circulating FountainScape all within the same space - and the birds will love it!

Are they a breeding ground for mosquitoes?

No. Mosquitoes need 7 to 12 days to lay and hatch eggs, and any standing water in a RainGarden will last for a few hours after most storms. If you have a decorative fountain in a Water Retention RainGarden, the water is constantly filtering and re-circulating. Mosquitoes are more likely to lay eggs in stagnant water in bird baths, storm sewers, and lawns than in a sunny RainGarden. Also RainGardens attract dragonflies, which eat mosquitoes!

Do they require a lot of maintenance?

RainGardens can be maintained with very little effort after the plants have been established.  Just like a regular perennial garden, some weeding and perhaps watering will be required in the first two years. Some thinning may be necessary in later years as the plants mature.  In fall, you will need to winterize your Water Retention RainGarden by removing the pump and storing it indoors until spring.

Is a RainGarden expensive?

It doesn't have to be. If friends and family help with the labour, the main cost will be purchasing plants. Water Retention RainGardens require specialized technical experience and are best installed by a professional.

If you are considering building a RainGarden on your own, do yourself a favour and first read Rain Gardens - A How-to Manual For Homeowners. (Courtesy: University of Wisconsin & Wisconsin Department of Natural Resources)