What is a rain garden?

A rain garden is a plant-filled shallow depression that collects rainwater (stormwater) runoff. Rain gardens are a great do-it-yourself project for homeowners to manage small amounts of stormwater on their own property.  By directing runoff into the garden, the rain that falls on rooftops, driveways, and other impervious surfaces on your property infiltrates into the ground. The water in the ground recharges local and regional aquifers instead of running off across roads and parking lots eventually polluting local waterways.

Rain gardens are beneficial in many ways

In addition to keeping local waterways clean by filtering stormwater runoff, rain gardens also help to alleviate problems with flooding and drainage. Rain gardens are attractive and functional features that, enhance the beauty of yards and communities. When planted with native plants they provide valuable habitat and food for wildlife. like birds and butterflies and they can reduce the need for expensive stormwater treatment structures in your community.

 Selecting Plants for the Garden

When considering plants for rain gardens, remember that the they are flooded periodically and can go through dry times.  Plants in the middle of the garden, where it is deepest, should be the most adapted to very wet conditions and able to withstand being covered by water for a day or more.  Plants on the edges of the garden should be able to be briefly flooded with water, like a few hours. Be sure to stabilize the raised bank around your garden that holds the water in grass or dry-tolerant native plants as well.

Native Plants for Rain Gardens

Native plants are a great choice for rain gardens.  Planting natives helps protect New York’s biodiversity by providing food and habitat for birds, butterflies, and other wildlife. Natives have evolved in our environment over many years and many of our wetland and riparian species are adapted to alternating periods of wet and dry.  The deep roots of natives absorb and filter runoff more effectively than the short roots of many turf grasses and other ornamental plants – making them a perfect fit for rain gardens!

Swamp milkweed, common boneset, cardinal flower, blue flag iris, Joe-pye weed, and white turtlehead are just a few of our native flowers that are happy in rain gardens.  Shrubs including buttonbush, bayberry, ninebark, summersweet, and winterberry can also be added if the garden is large enough.

Right Plant, Right Place

When constructing the garden you should consider if the site is sunny or shady in order to select the best plants. Remember – you need 6 hours or more or sun to be considered ‘full sun’.  It is easiest to find plants that work well for rain gardens that need sun, so keep this in mind when planning the location of your rain garden.  Just like with any other garden, think about what variety of height, color, and blooming period you would like as well. Mix a variety of flowers, grasses, sedges, for different shapes and textures above, and different root depths below the surface.  Shrubs are great in rain gardens too, if you have the space.  Consider planting flowers in masses of color to attract birds and butterflies.  Follow the tricks the professionals use and group plants in odd-number clumps, using 3, 5, or 7 (or more – just stick to odd numbers) of the same plant all together.  This way your rain garden is not only stopping stormwater runoff but is also providing you with a beautiful landscape to enjoy all summer long.

Get Outside and Get Inspired

Rain gardens aren’t just for homeowners. Here at New York State Parks, we use them to help manage stormwater on our properties too! Many local parks or other public places have rain gardens you can stop by and see.

In the Capital District area, there are rain gardens at Saratoga Spa State Park, Grafton Lakes State Park, Moreau Lake State Park, and Mine Kill State Park. Many of these sites also use other environmentally friendly practices for managing stormwater such as porous pavement as well.

If you want to learn more about rain gardens, check out these great step by step how-to manuals that are available for free online

• Rain Gardens: A how-to manual for homeowners.
• Rain Gardens: A design guide for homeowners in Connecticut.
• The Vermont Rain Garden Manual

Post by Emily DeBolt, State Parks