How to Make a Rainwater Garden
A rainwater garden is not just a beautiful addition to your outdoor space it’s also an environmentally friendly way to manage rainwater runoff and protect local waterways. With the right planning and care, you can create a rainwater garden that thrives throughout the year. Here’s how to get started!
What Is a Rainwater Garden?
A rain garden is an excavated depression in the landscape that is planted with wetland or wet-tolerant plants. It captures a portion of stormwater runoff from a targeted area (i.e., rooftop, walkway, or driveway). Even if it intercepts the first one inch of rain and the rest overflows, it will still capture about 90% of the total annual rainfall.
The idea of rain gardens is gaining popularity, and there are a ton of online resources available to get design inspiration. Even the PBS mainstay “This Old House” has an educational page to aid with the design process!
Choose the best location:
Where does your stormwater flow? A rain garden is designed to infiltrate water, so it is best to build your rain garden in an area where rainwater will feed into it from downspouts, driveways or low points in your yard.
1.At least 15 feet away from your home and downhill from any foundation.
2.Should not be placed over a septic tank or underground utility lines.
3.The idea of rain gardens is gaining popularity, and there are a ton of online resources available to get design inspiration. Even the PBS mainstay “This Old House” has an educational page to aid with the design process!
4.If you want to keep any trees, keep it out of their drip line.
5.Do not select an area that is already wet due to high groundwater or an area that already receives water from other locations, so you do not overwhelm your rain garden, and divert other water away (it will defeat the benefit of the rain garden)
6.Think about the many kinds of soil. The ideal soil types are silty or sandy sands. A siltier soil type can also be enhanced by adding and blending compost. However, a rain garden cannot be planted in clay soils. The USDA National Database Mapping of Soils is a useful place to look, as is excavating two feet to see the soils.
2.Creating Contours:
To make the rain garden, start with an existing depression in your yard, or create a new one with a shovel. Don’t just remove the topsoil, ensure that there is ample soil left to capture water. It’s essential to have sufficient soil in the rain garden basin as a medium for plant growth. Your rain garden will need at least 6 inches of soil for it to function correctly.
The way water drains through your new garden depends on the texture of your soil. If you have too much sand in your soil, rainwater will drain off the ground too quickly. Topsoil and compost are needed to fix this. Too much clay in your soil causes water to accumulate beyond your desired levels in your new rain garden. Adding two parts sand, one part compost and one part topsoil is a great way to improve drainage.
3.Design Your Garden:
Decide on the size and shape of your garden. Use a garden hose or rope to outline the area. The design should have a gentle slope leading toward the garden to guide rainwater into it.
The garden can be layered, with the sides being a little higher for overflow and the center being the deepest spot where water gathers.
4.Select the Right Plants:
Plant choices for this kind of garden are rather uniform, despite the fact that soils and growing zones differ greatly across the nation. Good rain garden species include asters, daylilies, iris, sedum, coneflowers, artemisia, and sedge. For other possibilities in your area, speak with other garden professionals or the university extension office in your area.
Choose plants that have “average to moist” water requirements listed on their tag. Position them in the deepest parts of your rain garden. On the higher edges of the bed, position plants that thrive in “average to dry” water conditions.
Buying moisture-loving plants for your rain garden might seem obvious, but don’t. Your garden’s moisture-loving plants will soon be left high and dry because it is made to drain in a day.
Although practically any plant that meets the proper moisture requirements can thrive in a rain garden, there are a few compelling reasons to choose native plants. Native shrubs, wildflowers, and grasses typically have extremely deep root systems that can reach depths of 10 feet or more.
Most native plants also cast off their roots annually, growing new roots and providing more soil aeration and pathways for water to flow. And because they’re indigenous, you know these plants will thrive in your zone and soil conditions.
5.Preparing the Garden Bed:
If there is grass at the proposed rain garden location, cut it out and maybe leave it in place to form a little berm to direct the water.
Depending on where you are, choose vegetation. When choosing plants, take into account whether your location receives sunlight or shade. The Old Farmer’s Almanac contains native flora as well as plants that grow well in both sun and shade. Wildflowers, ferns, bushes, and even small trees are frequently seen in rain gardens. For sections of the yard where water collects, water-tolerant native or edible vegetation is best.
Place the most water-tolerant plants in the center or lowest point in the garden where water will collect the longest. Plant natives whenever possible, especially in the outer edges where plants need to be more drought tolerant to avoid supplemental irrigation.
6.Direct Rainwater to the Garden:
Use downspouts, swales, or rain chains to channel water from your roof or paved areas into the garden. Be sure to avoid directing water too forcefully, as it can erode the soil.
Creating a rainwater garden is a rewarding way to combine beauty with sustainability. With a little planning and care, your garden will flourish year-round while helping the planet. Why not start today?