When you hear the phrase ‘rain garden’, you might think of a garden made of falling raindrops. That’s what came to mind the first time I heard the term. There’s a little poetry in the idea of a rain garden, but in fact, it’s a practical way of turning your garden into a cache for rainwater; about keeping rain where you want it, (and need it) rather than having rain run off madly in all directions.
Rain garden reduces rain water runoff, especially in torrential downpours, and keeps the rain working for you, rather than against you. The one pictured above has the building’s downspout directed towards the river of rocks, deflecting the water into the depression. A large roof can collect a significant amount of rain water, and a rain garden diverts water from overburdened municipal sewer systems and building foundations. Green Venture Canada defines rain gardens here, and has information about how to build your own rain garden, whether small or large.
A rain garden (also sometimes called a raingarden or a water garden) is a bioretention garden that is built in a shallow depression on your property and provides a simple yet effective method for controlling stormwater run-off. Strategically placed, rain gardens intercept and collect water that runs off roofs, driveways and yards and allow it to infiltrate the soil rather than to run off into storm sewers. Because this type of garden acts as both a natural biofiltration system and a temporary water reservoir, rain gardens are able to significantly reduce the amount of contaminated storm water that has direct access to our lakes, streams, and rivers.
Rain gardens aren’t always wet. Most of the time, a rain garden will be dry, but during a hard rainstorm, or a torrential downpour, the rain garden fills, collects and lets the water seep slowly into the ground. They are designed to meet the needs of a large rainfall, diverting it into a depression, letting it seep into the earth. To make a rain garden, start with a low section of your property where rain naturally drains, then direct water flow—such as from a downspout—toward that area. Plants that like to grow in wet areas are perfect to plant in your rain garden.
Natives are a natural for this because they tolerate short periods of standing water, are drought tolerant, and their deep roots make it easy for water to move down into the soil.