From erosion to beauty Using these savvy tactics, Tracy turned eroded land into a fertile hillside. Bind soil with sturdy roots: trees, shrubs, grasses,groundcovers. Remove weeds carefully. Make a rock garden. Place stones or boulders among plants to trap soil and moisture and slow water runoff. You'll get a more natural look by scattering rocks of a uniform type. Pictured: Creeping phlox, Louisiana irises, a curved grass path.