How to build an eco-friendly rain garden and protect your home.
Thursday, April 14, 2022
Building a rain garden not only boosts your curb appeal, but it can also help you conserve water and protect your home.
What is a rain garden?
A rain garden is a depression in the landscape that collects rainwater before it can enter the sewer system. The depression – typically just six to eight inches deep – is filled with native plants, especially those with deep root systems. Together, these features help to purify water as it percolates into the ground.
Rain gardens are often planted strategically close, but not too close, to your home to control runoff. Instead of rain running directly from your roofline to your driveway and into the sewer, you are able to redirect it away from your home’s foundation and toward your plants.
Why should you plant a rain garden?
Probably the biggest reason people plant rain gardens is to conserve water. As we add hardscaping to your homes – driveways, concrete paths, decks – we obstruct the ability for water to re-enter the ground. Surprisingly, the typical lawn can also be an obstruction. According to Groundwater.org, “Compared to a conventional lawn, rain gardens allow for 30% more water to soak into the ground.” And while rainwater is running off our roofs and over driveways, it’s taking dirt, chemicals and other pollutants with it. That means the untreated water entering the sewer system can then empty into our natural waterways, polluting them in the process. A rain garden can filter out up to 80% of that sediment.
In addition to naturally cleaning the water, rain gardens can help you use less water in the first place. The EPA reported in 2017 that Americans use more than 9 billion gallons of water outdoors every day, and a majority of that is for landscape irrigation. With a rain garden, there’s less reliance on sprinkler systems or your hose to keep your plants hydrated. Reducing water use is a good step toward becoming more sustainable for the environment.
Finally, rain gardens can actually help protect your home. When water pools around your house, you might find extra moisture in your basement. Your sump pump might have to work extra hard (what happens if it fails while you’re out of town?). Or, worst case scenario, that water starts to erode the concrete and mortar of your foundation.
How do you build a rain garden?
- Select a location that’s lower than your home so you can use gravity to direct rain runoff away from your downspouts or driveway. The garden should be at least 10 feet way from your house. Remember, we want it far enough away that it won’t damage your home’s foundation. You’ll also want to avoid planting your garden over septic tanks or near underground utility lines.
- Create a pathway for the water. This could be a bed of river rock or an underground pipe to funnel the water to the garden itself. Which route you go will be determined by both the aesthetics you’re going for as well as the distance the water has to travel. The farther your garden is from the water source, like your house’s downspouts, the more likely you’ll need to lay underground piping.
- Dig your garden. Like we said earlier, it’s usually six to eight inches deep. The actual depth depends on how much rain you get and how quickly your soil drains. You want a rain garden after all, not a pond. The average rainfall should drain away with about 24 hours. This will help keep your plants healthy, your home’s foundation safe and mosquitoes from settling in.
The overall size of your garden will depend on how much runoff you get. There are guides online that help you calculate if you have a roof of a certain size and average rainfall measures at a certain rate, how much runoff you can expect. If you aren’t into all the math, though, take comfort in knowing that you can simply plant a garden sized to complement your curb appeal. Even if it’s “too small,” it’s still better than nothing.
- Choose your plants. You want native species that do well with average to high soil moisture. Non-native varieties require extra water and care and could negate your attempts at being eco-friendly. While the flowers you choose will vary based on your location, consider daylilies, coneflowers and sedge as a starting point.
- Plant your flowers. Because your depression has a bowl-like shape, plant the varieties that love moisture the most in the base and those that need less water on the slope.
- Maintain your garden. While rain gardens are generally low maintenance once built, it pays to be vigilant, especially the first year when plants are young and still sending out their roots. Many experts recommend leaving a notch on the downhill side of your rain garden so that excess water can run out more easily without uprooting young plants. On the uphill side, some larger rocks or a natural barrier of some kind can slow the water as it comes in and doesn’t wash away your young plants.
During dry spells, you might need to water your garden occasionally. Fortunately, if you chose native plant species, you shouldn’t need to do this too often as those varieties tend to be fairly drought resistant.
We use so much water in our daily lives, inside the house and out. The good news is that even small changes can have a big impact on helping the environment. Get started with these sustainable curb appeal hacks at the Schlage blog.