Gardener’s Guide: How to Build a Rain Garden

Are you a climate-conscious gardener? Or perhaps your basement has seen some flooding and you want to divert rainwater from your home’s foundation? Whatever your reason, you want to know how to build a rain garden–and we’re going to tell you. But first, we think it’s important that you understand all of the benefits you’ll receive from building a rain garden in your yard. So here they are.

Benefits of a Rain Garden

When you create a rain garden, you essentially create a plant pond. Rain gardens are depressions in the ground to which you divert rainwater. Within these gardens, you plant deep-rooted plant species to help prevent erosion and control runoff. Whoops–we just gave away two of the benefits of a rain garden! Here are some more:

  • Remove standing water from your yard
  • Control runoff pollution via filtration
  • Reduce the potential for home flooding
  • Decrease mosquito breeding
  • Conserve water
  • Keep plants hydrated during dry spells
  • Recharge groundwater
  • Provide a habitat for various species, including pollinators.

No matter your motives, creating a rain garden will benefit you and your yard. Rain gardening is a passive form of water harvesting because it makes use of the earth’s resources. Active water harvesting, such as collecting rain with a rain barrel, does not make good use of the earth’s resources. Tip: rain barrels are breeding grounds for mosquitoes!

So now that you know the benefits, let’s get to it! Here’s how to build a rain garden in your own yard:

How to Build a Rain Garden

Ready to earn your landscape architect degree? Just kidding. But seriously, the first step to building a rain garden is designing one. Don’t worry; it’s easy. Just follow the steps below!

Choose your Location

It’s very important that you choose the perfect location for your rain garden. To prevent flooding, the garden should be at least ten feet from your home’s foundation, and it should be located downhill. You’ll want the rain garden to have a direct line of access to your rain gutter to maximize the amount of water it receives. In addition, the location should have full sunlight for at least six hours a day and should be kept away from large trees or utility lines. Here’s a checklist to make sure your site is perfect:

My site…

  • Is 10 feet away from my home
  • Located downhill from my home
  • Has a direct line of access to my rain gutter(s)
  • Receives at least six hours of full sunlight
  • Is not located near any large trees or utility lines
  • Has well-draining soil
  • Is 100-300 square feet

Have your location picked out? Great! Here’s the next step:

Design the Garden 

Your rain garden is going to need a berm, or a raised strip of land that borders the rain garden. Think of the berm as the rim of a soup bowl; it keeps the liquid inside. Ideally, your location would already have a natural berm, but you can make one yourself.

You’ll then want to determine the size and depth of your garden. Most rain gardens will absorb and drain water within 24 hours, but you should test your soil first to get an accurate idea. (You can test this by digging a small hole in your yard, filling it with water, and timing how long it takes for the water to drain.) Rain gardens are usually one foot deep.

Once this is finished, you’ll need to design the swales, which are the stony paths that lead rainwater from your gutter to your garden. This isn’t too difficult. All you’ll need is river rock!


example of a swale in a rain garden


Lastly, you’ll want to design an overflow zone for major storms. This zone will need to be slightly lower than your rain garden and will need to direct the flow of water away from your home (as well as your neighbors’).

Here’s a general idea of what a rain garden looks like:

rain garden diagram

Here’s a handy checklist to make sure you have every element of your design on paper:

  • Berm (the rim of your rain garden)
  • Rain garden (100-300 square feet, 12 in. deep)
  • Swales (stony paths leading rainwater from gutter to garden)
  • Overflow zone (slightly lower than rain garden and directed away from homes)

Once your design is on paper, you can build your rain garden. But what comes next? Every gardener’s favorite thing: plant selection!

Rain Garden Plant Selection

Once your rain garden is built, you’ll want to start planting. But you can’t plant just anything. Here’s a list of some good rain garden plants:

  • Aster
  • Daylily
  • Iris
  • Sedum
  • Coneflower
  • Artemisia
  • Sedge

Of course, locations differ and so do plant species. The best plants for a rain garden are native species, and this is because these species are best adapted for your region’s moisture conditions. You can check out this site to find a list of native rain garden plants in your state.

Once you’ve selected your plants, you need to plant them in the garden. High-moisture plants should be planted in the middle of the garden, as they will receive the most water. Low-moisture plants should be planted near the berm or ridge of the rain garden.

For climate-conscious gardeners or pollinator supporters, ensuring your rain garden is safe and ecofriendly is important.

When it rains, surface water that is not absorbed into the ground flows over the land in the form of runoff, soaking up pollutants, such as fertilizer, sediment, bacteria, and petroleum byproducts, which can negatively affect plant and wildlife.

A rain garden can reduce the amount of runoff by storing rainwater in the ground.  Rainwater is directed from a source to a depression in the ground via a swathe. Native plants then absorb the water that is directed toward them while excess water flows into the depression. The ponding zone at the bottom of this depression allows pollutants in the runoff to settle, thus reducing the effects of pollution on plant life.

While pollutants are filtered at the bottom of the rain garden, rainwater sitting in the depression is available for animals and insects. To ensure that your rain garden is as safe as possible, limit your use of harmful chemicals. One way you can do this is by switching to xVital. Our nitrate water fertilizes plants without leaving any runoff. You can learn more about it here.

For other ways to design your yard, click here.


Benefits of Planting a Rain Garden

Soak up the Rain: Rain Gardens