How to install a rain garden?

Rain Garden Design and Purpose

A rain garden is a shallow, planted depression that captures runoff from roofs, driveways, and impervious surfaces, allowing water to infiltrate slowly into soil instead of overwhelming storm drains. These features reduce flooding, filter pollutants naturally, recharge groundwater, and provide habitat for beneficial insects and wildlife. In Charlotte's Piedmont region with clay-heavy soils, rain gardens significantly improve drainage while reducing erosion.

Rain Garden Installation Steps

1. Location Selection: Position 5-10 feet from home foundation and utility lines. Calculate collection area (roof or driveway square footage) to determine appropriate garden size.
2. Excavation: Dig basin 4-8 inches deep in slight depression. Size: roughly 5-10% of collection area square footage.
3. Soil Preparation: Create soil mix from native clay, compost (20-40%), and sand to improve infiltration while maintaining structure.
4. Plant Selection: Install native perennials tolerating both wet and dry periods (coneflower, black-eyed Susan, Joe-Pye weed, native sedges).
5. Mulching: Add 2-3 inches of mulch to retain moisture and suppress weeds during establishment.
6. Drainage Check: Verify water infiltrates within 24 hours; adjust soil composition if drainage is inadequate.