Column: Rain gardens have downsides

By Pam Pommer

Guest Columnist


Last month I wrote about when gardening becomes a chore.

While talking calls at a local landscape department, I’ve come to realize that I’m far from alone.

As the population ages, we want gardens that require less maintenance. Or, we want someone else to care for them. I’m also learning that although many people are eager to have someone create something beautiful in their yard, many don’t realize the work involved to care for it.

In light of that, I’m now looking at the rain gardens in Bloomington with increasing skepticism. To be honest, I didn’t even know what a rain garden was until last fall. I was driving to my sister’s house in central Bloomington when I noticed something strange along a street that had been under construction that summer. Some of those neighbors were left with large deep pits in their yard. They must be furious.

Then I learned they had chosen to have rain gardens constructed in their yards to filter sediments out of street water run off before it enters our rivers and lakes. Sounds like a nice idea, but what are the drawbacks to these features?

The University of Wisconsin has a guide for rain gardens for southeast Wisconsin. It states: “A typical rain garden is between four and eight inches deep. A rain garden more than eight inches deep might pond water too long, look like a hole in the ground, and present a tripping hazard for somebody stepping into it.”

Bloomington’s rain garden information handout states that they are a “shallow flat basin with gentle side slopes.” Yet many that I see in Bloomington drop off rather abruptly and then dip to a depth of at least three feet.

All the articles I found stated that these gardens are designed to hold water for no more than two days. Yet some of these Bloomington gardens have been holding water for almost a week.

Despite claims to the contrary, some of these gardens certainly look like breeding grounds for mosquitos. In addition, I think they are drowning hazards for small children. Can you imagine running through a neighbor’s yard and suddenly falling into a 3-foot pit? Then imagine if there is a foot of water at the bottom.

While some have drained rather quickly during this rainy spring, water or muddy bases remain in a few. And the plants in those gardens don’t look very happy. These looks more like swamp pits than landscaped gardens.

Although most handouts and articles emphasized that some maintenance is required to keep them useful and aesthetically pleasing, I’m not sure people realize what they are getting into when they have these constructed. Maintenance can include: replacing mulch, digging out dead plants and replacing them with new ones, removing accumulated sediments, removing weeds, etc.

I received a call from a local business the other day who had complaints about their rain garden. They said plants kept dying due to excess water and all the sediments from parking lot runoff. They were getting tired of paying to have people come out to remove the sediments and replace the plants.

I also checked out the rain gardens that were installed in Bloomington back in 2009. For the most part, these were much more elaborate. Some had landscaped stone retaining walls with tiers of plants leading to the bottom of the basin. And it was encouraging to see that eight years later, most of them looked really good and well maintained.

Overall, however, I think that while rain gardens might sound like a nice ecological earth-friendly idea, people need to carefully contemplate if it’s worth the investment of time and money to have one installed. And they should also consider that it might be a deterrent when it comes time to sell your home. If not properly constructed and maintained, you could end up with an albatross on your hands.

And to be honest, I hope taxpayer money isn’t being used to fund experiments that assume residents will happily maintain them.


Pam Pommer, a graduate of Lincoln Senior High School, lives in Bloomington, where she enjoys gardening and spending time with her shelties. She can be contacted at [email protected]