With the increasing frequency of heavy storms across Québec, some homeowners are looking for sustainable strategies to prevent water pooling on their property.
But what if you turned this challenge into an opportunity to enhance your landscaping and fight the effects of climate change? This is exactly what a rain garden aims to do. It’s a simple, natural, and effective way to manage stormwater runoff… and attract butterflies, birds, and pollinating insects to your backyard.
What’s a Rain Garden?
A rain garden is a landscaping feature comprising a slight depression filled with plants that tolerate both wet and dry conditions. It can look like a large flowerbed.
It works by naturally collecting and filtering rainwater or runoff from your roof, driveway, or yard, by allowing it to seep into the soil instead of entering the sewer system. It can also serve as a catch basin to remove excess water from elsewhere on the property.
Why Build a Rain Garden on Your Property?
Here are just some of the reasons why you should create your own rain garden:
- It reduces the risk of flooding around your house.
- It improves water quality by filtering out pollutants (oils, fertilizers, deicing salt, etc.).
- It eases the strain on municipal sewer systems, which can help prevent backups and costly damage for taxpayers.
- It creates a habitat zone, attracting beneficial insects, birds, and even frogs.
- It adds a unique, beautiful feature to your landscaping.
Where to Start?
1. Choose the Right Site
The best spot for a rain garden on your property is where water already naturally accumulates after it rains. It must be at least 3 metres’ distance from the home’s foundation to avoid directing water too close to it. Areas where the soil is very compacted or that drain very slowly are likewise unsuitable.
2. Determine the Size
As a rule of thumb, a rain garden’s size should range between 10% and 30% of the roof’s or yard’s surface area from which the runoff will be collected. It will still deliver the same benefits if it’s a little bigger or smaller than the general recommendation, however.
3. Dig and Fill
Dig a basin approximately 15 cm to 30 cm deep, then fill it with layers of drainage materials (gravel, compost, topsoil). The bottom layer must be permeable, so no waterproof membrane. You must also plan an overflow area to contain extra water during heavy storms.
4. Select Suitable Plants
What’s the secret of a well-designed rain garden? Plants that thrive in damp soil… but not waterlogged soil! Opt for perennials, grasses, shrubs, or native species that tolerate flood and drought cycles. Here are a few ideas:
- Blue flag iris (Québec’s floral emblem)
- Butterfly milkweed (which attracts monarch butterflies)
- Carex (also called sedge, a very resilient type of herbaceous plant)
- Purple coneflower
- Bee balm (beloved by bees)
5. Add Rocks and Gravel
Include rocks of various sizes as well to give your garden personality and create a more biodiverse environment.
6. Give it Some TLC
Once established, a rain garden is very low maintenance. You just need to weed every now and then the first year, water during long periods of drought, and cut down perennials in fall or spring. The result: a practically self-sufficient patch of nature!
Bonus: Financial Assistance Is Available!
Certain municipalities offer financial aid and expert advice to residents wanting to build a rain garden, namely as part of their stormwater management plan. Check with your city or RCM: you might be able to make your project happen for less than expected.
Rain gardens are good for the planet, beneficial for your backyard… and a feast for your eyes! Whether you decide to build a rain garden out of love for gardening or the environment, it’s an ingenious and actionable way to make a difference. Time to say bye-bye to floods and hello to flowers!