Just like any other area of aesthetic endeavor, landscaping trends change from season to season and decade to decade. Homeowners in the 1920’s wanted to bring nature into their spaces, so birdbaths, fish ponds, and butterfly gardens were all the rage. In the 1950’s and 60’s the boom in middle-class consumerism and modern materials saw a huge uptick in the popularity of fencing and ornamental materials made from coated metal and plastic.
Today’s market values ecological sustainability and conservation, and one of the offshoots of this green movement is the popularity of rain gardens. This is a garden that’s designed and located to take advantage of rainwater running off the roof of a house. It’s estimated that the roof of a typical American home can shed up to 500 gallons of rainwater for each half-inch of rainfall. With a bit of research and some strategic planting, you can create a lush, self-sustaining garden that won’t tax your local resources. This is a clear benefit to the environment, but this also means that you get to enjoy a healthy, growing greenspace with minimal effort, so that’s a clear win-win situation for you and Mother Nature. Rain gardens also help control drainage and keep excess water from seeping into your house by feeding it to a habitat full of deep-rooted, thirsty plants.
How do you get a rain garden started?
The first and most important step is to identify an area that’s suitable for a rain garden. What you’re looking for is a spot that is fed by downspouts, roof runoff, driveways, or just a low point in the yard. To avoid a lot of difficult landscaping, you’ll want to make sure that you have a minimum slope of 2% (that means that the height of the ground decreases by 1 inch for every 4-1/2 feet of length) running into your rain garden. If the water isn’t already flowing directly into this low spot, you can direct it with a concrete or rock channel, also called a “swale”. If you have guttering, you may be able to connect a metal or vinyl tube directly from your gutter. For a cleaner look to your yard, you can bury that tube in the ground as well.
There will be times when you get more rain than usual, so be sure that your garden is at least 10 feet away from your house in order to prevent excess water from collecting near your foundation. By the same token, your rain garden may get too much water and overflow, so having a channel to direct excess water away from the garden isn’t a bad idea either.
How big should it be?
The size is up to you, but you want to make sure that it’s able to drain off a full dose of rainwater in about 24 hours. The best way to test this is to dig a coffee can-sized hole in your potential spot and fill it with water. If it drains at about one inch per hour, then the ground will probably be able to absorb a heavy rain within one full day.
While low, water-collecting spots are ideal, you may also need to build a berm or small earthen wall to help keep the water contained. Of course, all this depends on the specifics of your yard and climate.
Choosing your plants
Because you’re going to use the naturally occurring rainfall to feed your garden, you’ll want plants that are best suited to your local climate. Native grasses and wildflowers usually have very deep root systems and those deep roots help to provide pathways for water to flow through the soil.
While what is considered native varies from climate to climate, we generally find that asters, day lilies, iris, sedum, coneflowers, and Artemisia generally work well. If you’re not familiar with your local university extension, now is a good time to call them up and get their advice on what will work best for your area.
As a rule of thumb, try to go with plants that have “average to moist” or “average to dry” water requirements listed on their label. You might want to choose moisture-loving plants, but your rain garden is designed to drain water within about 24 hours, and those plants will quickly be without the moisture that they crave.
A successful rain garden is always customized to a very specific terrain and climate, so there are a number of details to keep in mind.
Red Valley Construction is no stranger to finding innovative solutions for unique spaces. If you’re after something tailored to your environment or if you’d like something that’s green in more ways than one, give our experts a call and let us see what we can dream up together.