Rainscaping Guide: Is a Rain Garden Right For Your Site?

A rain garden is not always the best choice for every landscape. Use the flowchart below to figure out if a rain garden is a good fit for your site. Click on the purple or blue boxes to go to that topic or use the links below the chart for help in examining your site.

Is a Rain Garden Right for Your Site? flowchart


Link to Work Wonders with Woodlands section Link to Conquer Compacted Soils section Link to Stabilize Steep Slopes section Link to Let Loose on Low Wet Areas section Link to Design & Build a Rain Garden section Link to How to Conduct a Percolation Test Link to Examine Slopes Link to Woodlands and Rain Gardens section

Examine Slopes

Gentle Slope
A rain garden is ideally located on a gentle slope uphill from the low point in your yard, perpendicular to the flow of water. Shapes that are oval or kidney-shaped are most commonly used. Shape is also determined by the surrounding landscape, such as other planting beds, sidewalks and driveways. This helps to maximize the amount of water intercepted and the ability of the rain garden to dissipate the energy (velocity) of the runoff. Also consider shaping your rain garden in a way that complements existing lines (bed borders, sidewalks or paths, etc.) and the surrounding design style.

Little or No Slope
If there is little or no slope, the soil needs to be well-drained, or your rain garden will become a pond. Round or rectangular shapes are most commonly used.

Moderate Slope
If the site has a moderate slope, consider building a linear rain garden or bioswale along the contour of the hillside. The use of erosion control fabric may be needed on a moderate slope to prevent erosion while plants are becoming established. There are many forms of biodegradable erosion fabric: mats, netting or blankets (see our Erosion & Sediment Control Resources section).

Narrow Long Slope
If the site has a narrow, long slope, consider a series of small rain gardens stepped along the slope. You can also connect the rain gardens with a meandering bioswale that resembles a dry stream bed with stones and plants to help slow down the water.

Steep Slope
If the site has a steep slope, a successful rain garden may be difficult to achieve. Digging into a steep hillside may destabilize the slope. In addition, infiltration of rainwater into the soil may be minimal as water may migrate laterally and break out on the slope, potentially causing further erosion. See other techniques for stabilizing steep slopes.

Rainscaping Guide Quick Links

What is Rainscaping?
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The Missouri Botanical Garden Rainscaping Guide is partially funded by the Mabel Dorn Reeder Foundation and US EPA Region 7 through the Missouri Department of Natural Resources (subgrant number G11-NPS-15), under Section 319 of the Clean Water Act.