Starting a Rain Garden: Site, Sizing, and Plant Selection

How to start a rain garden — site selection to capture runoff, sizing the basin, selecting plants by zone and moisture tolerance, and the three-zone planting approach that makes rain gardens actually work.

When to plan and plant

Plan in fall or winter, using rain events to observe where water actually flows on your property. Plant in fall (preferred) or spring. Per Penn State Extension, "observing your property during a significant rain event is the most useful site assessment step — you see exactly where water collects, where it flows, and where it exits the property."