How to Plant a Backyard Rain Garden

It’s springtime, and many people are putting on their gardening gloves and planting some tomatoes or maybe tulips in their backyard. But there’s another kind of garden that you might want to consider, especially if you live in a rainy place with old and overburdened sewers.

That’s what folks in Parma, Ohio, have done. The Cleveland suburb is a typical neighborhood with homes, lawns, and sidewalks, but there’s something missing: grass. Jen Greiser, a natural resource manager for the Cleveland Metroparks, explains that this is intentional. “For homeowners that signed on to the project, we installed what we call ‘right of way’ rain gardens, and so we worked with a contractor to take up the grass and dig some depressional planting beds and install some plants,” said Greiser.

Heavy rains can overload the sewers in some cities and cause raw sewage to enter waterways. Photo credit: wikimedia — Heavy rains can overload the sewers in some cities and cause raw sewage to enter waterways. Photo credit: Wikimedia

This project is one of many initiatives in this area and across the country that use plantings and greenery to help trap stormwater.

Northeast Ohio is a rainy place, and all that water -- if not absorbed into the soil -- runs off, mixes with pollutants and sewage, overloads the wastewater treatment plants, and ends up spewing out untreated into Lake Erie. This isn’t a good thing for people or wildlife or the lake’s overall ecology.

One of the key strategies for keeping stormwater out of the lake and in the soil is to create what’s called “green infrastructure.”

Stormwater runoff can be stemmed on a large scale with stuff like urban trees, wetland protection, permeable pavement, and floodplain management. But it can also be done on a smaller scale by individuals.

Purple Coneflowers, also known as Echinacea, are an attractive plant for a rain garden but watch out for deer, who love to munch them. Photo credit: Flickr / Karen Blaha

In the spirit of springtime, the Metroparks’ Jen Greiser shared some tips with me on how to plant a backyard rain garden that can reduce local runoff and provide some attractive landscaping.

To get started she suggests a little observation during the next rainy day. “Just put on a raincoat, grab an umbrella, run outside, and stand out there for a little while,” said Greiser. Your neighbors might wonder what you’re doing, she warned, but don’t let that deter you. It’s important to find out where the water’s pooling up. This is the spot to plant your rain garden. And it doesn’t have to be huge: it can fit right into other landscaping schemes.

Next, it’s time to get your hands dirty with some digging. “Instead of our traditional planting beds that are raised above the ground, we’re kind of flipping that over and we’re going to have a more bowl-shaped area for planting,” said Greiser.

Plants with deep root systems, like this switchgrass, are good choices for a backyard rain garden. Photo credit: Wikimedia / Lee R. DeHaan

You want to fill out your bowl with plants that have deep root systems. Native grasses and shrubs take their roots deep into the ground, so they loosen up the soil and allow for more water to seep in. A mowed lawn, in comparison, has a really shallow root system.

You can also pick deep-rooted ornamental plants, but watch out for the tastier varietals like cardinal flower or purple coneflower, which Greiser says can just be deer candy.

You might also want to consider some soil amendments, especially if your soil contains a lot of clay. Mixing in some sand or compost helps water infiltrate through heavy clay. If your backyard soil is already pretty sandy, then a shallow rain garden should work just fine.

Another option for controlling stormwater on your property is to place a rain barrel beneath the downspout of your gutter. The collected water can be used for watering plants or washing cars. Photo credit: Flickr / Digi_D

Then wait for the rain. Your garden should soak up the water in just a day or two, so there’s no standing water.

Greiser says backyards are an important part of overall stormwater management plans for areas like northeast Ohio, where residential parcels abound. “While they seem small in and of themselves, the residential areas make up such a great percentage of our land use here, so they’re really critical, and to the extent that we can get whole neighborhoods involved, it’s a cumulative effect,” she said.

Some communities even offer incentives to residents who plant rain gardens in their yards. The Northeast Ohio Regional Sewer District will knock off 25 percent from a homeowner’s stormwater fee (if and when those fees resurface after ongoing court battles). Other metropolitan areas, like cities in New Jersey and Washington, give a major rebate to cover the cost of a rain garden installation. One pilot program in Cincinnati actually paid

When in doubt, think like a rain drop. Wherever water pools up in your yard is the best spot to plant a rain garden. Photo credit: Pixabay / gama

people to plant them.

Jen Greiser says would-be rain gardeners should aim to get their plants in during the spring to soak up all the May showers, though a fall planting would also work well.

If your green thumb is a little rusty, just remember to think like a raindrop and you can’t go wrong.

Additional Links

Rain Garden Manual for Homeowners
A Homeowner’s Guide to Stormwater Management
Rain Gardens - Plants, from Penn State Extension
Rain Garden Plants
Ohio Native Plant Suggestions for Horticultural Plantings
Your Backyard: A Stormwater Sponge