Rain Gardens: A Detailed Guide For Beginners

Rain gardens are a great way to control damaging runoff in your yard. While the main purpose is to capture and filter rainwater, they are beautiful too! In this post, you will learn all about rain gardens, including the purpose and benefits, how they work, and tips for creating your own.

Have you ever considered creating a rain garden? Or for that matter, wondered what one is? Unlike a water garden, a rain garden captures, directs, and filters stormwater runoff as it flows through your yard.

This protects the valuable topsoil from erosion, but also offers great environmental benefits for local waterways by filtering out debris and pollutants.

Ultimately, it’s all about capturing and directing the water where you want it to flow, for the most benefit, and the least damage.

In this guide you’ll get a detailed introduction to rain gardens, so you can decide if having one is right for your yard!

What Is A Rain Garden?

Unlike a regular flower garden, rain gardens are designed to capture rainwater runoff. They have a depressed area in the center, called a basin, where water pools, and is later absorbed into the ground.

On the surface, it looks like any other flower garden, but the middle part is lower than the outer edges.

Plants in and around the center depression loosen the soil and utilize some of the water, creating a low maintenance garden.

What’s The Purpose Of A Rain Garden?

The purpose of a rain garden is to slow the flow of rainwater runoff and absorb it into the ground, which naturally filters out debris and pollutants.

They also allow us to control how the water flows through our yards, and prevent problems like pooling and erosion.

Why Is Rainwater Runoff A Bad Thing?

Runoff is a major problem, particularly in urban and suburban areas. Stormwater runs off of our roofs, into our gutters and downspouts, and then out into the street as fast as possible.

Not to mention all the cement and blacktop surfaces, where the water never has a chance to be absorbed into the ground.

Along the way, this fast-moving water picks up all kinds of debris and pollutants, and carries them along into the storm drains.

In Minnesota, we have many beautiful lakes and rivers. All of the runoff from the storm drains are dumped straight into the local waterways.

Directing water into a rain garden prevents it from running off into the streets, taking your soil and mulch with it. It also helps to keep dirt, fertilizers, and yard waste out of our local waterways.

My Story

Erosion used to be a huge issue in our yard. Every time we got a heavy rainfall, the water would flow between our houses like raging mini-rivers.

This would cause large areas of mulch and dirt in my front gardens to be washed away, causing lots of (expensive!) work to rebuild.

Plus, the middle of our backyard turned into a swampy mess of standing water during storms. Adding a rain garden to the spot where the most water comes into our property has been a game-changer!

It has worked wonders to prevent a swampy backyard, slow down the mini-rivers, and keep the runoff from taking my mulch and soil along with it.

How Do Rain Gardens Work?

Water is directed into the center of the rain garden, and soaks into the soil rather than running off into the streets. So it catches the runoff, and also slows it down, preventing erosion.

Excess water drains away in a convenient direction, allowing you better control of the flow of water through your yard.

Plus, the plants in the basin are not only beautiful, they server a purpose. Their deep roots loosen the soil, and help the water soak into the ground faster.

Why Build A Rain Garden

If you’re unsure whether a rain garden is a good choice for your yard, take some time to observe the water during the next heavy rainfall.

Pay attention to how much drains off your roof, and runs into the streets. During times of heavy rain, our street is turned into a mini-river. The rushing water washes away everything in its path, and causing plenty of backup at the storm drains.

One of the reasons runoff is a particularly huge problem in our yard is because we live downhill from many of our neighbors. You could see the amount of damage and erosion it caused, especially after a major storm.

Not only was it super frustrating to see all that soil and mulch wash away, it was getting costly too. One year I had to replace the eroded part of the front garden area four or five times! That was no fun.

How To Build Your Own

The first important thing to note is that you can’t just put a rain garden anywhere. You have to do a little bit of research and planning to figure out the best location.

You want to put it in a spot where it will capture runoff as it flows through, rather than somewhere that water already pools. There are also several areas to avoid.

So, if you want to put one in your yard, then make sure you take the proper steps so it will work correctly. Once the time comes, you can learn the exact steps for building one here.

Tips For Planting Your Rain Garden

When it comes time for planting, you may find that you’ll end up facing the same challenge as I did. My project was delayed a bit because we had a bunch of rain that year.

And of course, being a rain garden, the basin kept filling up with water. Well, at least we knew it was working! But all that water made it impossible to plant most of the garden.

If this happens to you too, you can cut a temporary trench in the outlet to allow the water to drain from the basin immediately, without absorbing into the ground.

That way, it will stay dry long enough to get everything planted. After the plants become established, fill in the trench so the basin will be able to capture water again.

Related Post: 29 Rain Garden Plants For Sun Or Shade

Rain Garden Care & Maintenance

You might be wondering what type of maintenance a rain garden requires, or think that it will be hard to care for.

But guess what? Caring for it is basically the same as any other garden area you have. The only thing that’s different is that you won’t be able to walk into the center when it’s full of water.

You’ll also find that you won’t need to worry about watering it very often. In fact, once the plants are established, they won’t need to be watered at all, unless you have a long dry season, or period of extreme drought.

I find that weeding is also less work, because most weeds can’t become established in the center where the water pools. So I rarely need to weed in there.

Most of my weeding is around the outside and top edges. And, as long as you maintain a 3-4″ layer of mulch over the soil, the weeds that do take hold will be much easier to pull.

Rain Garden FAQs

In this section, I will answer some of the most common questions I get about rain gardens. If your question isn’t answered here, please ask it in the comments below.

How much does it cost to put in a rain garden?

The cost of a rain garden varies widely. If you do all the work yourself, it will be much cheaper than paying someone to do it. Also, the larger it is, the more materials and plants you will need to purchase.

To give you an idea, mine is about 150 square feet, and it cost $500. That included everything: compost, mulch, rock, and all the plants I needed to fill it.

Be sure to check with your city, country, or local watershed district to see if they offer any grants. As it turns out, the bulk of mine was paid for by a grant from my city.

Will my rain garden become a breeding ground for mosquitoes?

No! When properly designed, the water in a rain garden will drain within 24-48 hours. It takes mosquitoes much longer than that to mature from egg to adult, so they won’t have time to breed in the temporarily standing water.

Do rain gardens have standing water?

Yes, but only for a short time. They are not meant to be a bog, pond, or water garden that’s permanently filled with water. Any standing water typically drains within 24 hours.

Rain gardens can change the flow of runoff on your property, preventing erosion, and benefiting your local waterways, while still making your yard beautiful. It has made a huge difference in mine. I can see how much of an impact it would make if everyone had a rain garden.

Recommended Books

• Rain Gardens: Sustainable Landscaping for a Beautiful Yard and a Healthy World
• The Blue Thumb Guide to Raingardens
• Rain Gardens For the Pacific Northwest
• Rain Gardening in the South

More About Flower Gardening

• How To Grow Canna Lilies: Complete Care Guide
• How To Grow Zinnias: The Ultimate Guide
• Annuals vs Perennials: What’s The Difference?
• Peonies Care Guide: How To Grow Peony Plants

Do you have a rain garden? Tell us about your experience in the comments below!