What Is a Rain Garden?

Rain gardens are gardens specifically designed to absorb and manage rainwater run off. They are used to catch water from roof downspouts, parking lots, turf, and other surfaces. They typically are designed with some type of depression that allows water to collect and disperse into the soil.

To be successful, a rain garden needs to be sized correctly for the amount of rainfall it will be absorbing. It also needs to be designed with a plant palette that will ensure successful drainage and withstand the presence of temporary pooling water. 

Here's an instance where a rain garden was an appropriate solution for one of Our Land Organics’ clients:

Why Have a Rain Garden?

There are many good reasons to make a rain garden. For instance:

• Rain gardens can solve rainwater run off issues and improve drainage on your property.

• Rain Gardens are unique and beautiful landscape features. The unique growing conditions created by a rain garden allow the use of plants that you might not otherwise have the ability to grow. For instance, plants that enjoy living in temporary wet conditions that would otherwise not work in your yard work in a rain garden.

• Rain Gardens attract beneficial wildlife.We use a native plant palette in our rain gardens. Native plants are adapted to handle the unique demands of growing in a rain garden. The use of natives creates a habitat which attracts beneficial insects that can help keep your insect pressure down in your gardens. That’s a win.

• Rain Gardens improve our community's water quality. When you install a rain garden on your property, you become the change you want to see. Chances are you don’t like the idea of raw sewage flowing freely in your creeks and rivers! By having a rain garden, you are directly contributing to alleviating our regions combined sewer overflow problem. Thank you in advance!

Locating Your Rain Garden: The Do’s and Don’ts

Rain gardens can be a very useful tool for managing rainwater run off, but they’re not a “one size fits all” solution. Understanding when it’s appropriate to install a rain garden is key to a sustainable and successful garden.

A large contributor to success is locating a rain garden properly. When thinking about where to make a rain garden, consider the following.

• Proximity to structures. Make sure your rain garden is at least 10’ to 15’ away from any structure with a basement and also down slope from the structure.

• Proximity to existing trees. Do not locate rain gardens close to existing tree root systems or existing gardens, as the soil disturbance required for a rain garden could cause serious damage.

• Proximity to septic systems . The minimum distance that you want to locate a rain garden away from a septic system is 50’; otherwise infiltrated rain water could overwhelm the system.

• Slopes. Cincinnati is a hilly region with different grades of slope. Make sure the slope where you’re thinking about installing a rain garden will be under 12%. Anything steeper will involve slope stabilization issues that can be complex.

• Space for overflow. Ideally, your rain garden should be located such that if the rain garden fills up during a particularly heavy rain, the water can overflow to an area that can handle it (such as a creek, street curb, or sewer). This is your all-important Plan B.

• Utilities. Check with your local utility protection service to make sure your rain garden won’t be located near any utility lines are. In Ohio, you’ll want to contactOUPS; in Kentucky, contact 811.org

• Soil. If you live in the Cincinnati Metro Region, you probably have clay-based soil. You want to make sure that wherever you’re building the rain garden will have an infiltration rate of 1/2” to 1” per hour. Learn how to test your infiltration rate here. If you don’t have the desired infiltration rate with your current soil, you can usually amend compost into the rain garden to achieve this.

If you have made it through this checklist and still have potential areas where a rain garden will work, congrats! If not, there are definitely other green infrastructure options for your yard. See a list of them here.  

The Mosquito Fallacy

I often get the question about whether rain gardens will be a mosquito magnet for the yard. Thankfully, they are not!

Rain gardens are designed to drain rain water within 24 hours, if not within an hour or two. They are not wetlands. This amount of time does not allow mosquitos to complete their larvae’s 7-12 day life cycle. Additionally, your rain garden will more than likely be attracting insects and/or birds that like to eat mosquitoes.

Interested in a rain garden? We routinely consult with clients about rain gardens and install these gardens as part of our landscape design and installation services. We would be happy to learn more about your project and advise you regarding whether a rain garden is a good solution for your site. Contact us any time!