How can I fix my lumpy lawn? I think that earthworms are to blame for this problem.
—Roger Temple, Chadron, Nebraska
Earthworms are nature's aerator. They help open up the soil for better root penetration and water flow while incorporating organic matter into the soil where lawn and other plant roots grow.
Core aerating may help loosen the compacted soil and alleviate some of the problem. You may also want to top-dress the lawn with 1/4 to 1/2 inch of topsoil or compost. Rake to fill in low spots, smoothing out the soil surface.
Don't roll the lawn. This compacts the soil, causing a whole new set of problems.