Whether an unsightly patch or a thick layer that keeps air, water and light away from grass crowns and roots, dead grass doesn’t belong on a healthy lawn. Dead grass on an existing lawn can be the result of a number of causes, and its removal should address only the specific problem because you don't want to have to reseed the entire lawn.
Rake the lawn with a fan-shaped broom rake in the spring after the snow has melted and the ground is firm. Debris from this step can go onto the compost pile. Diagnose your dead-grass problem before going further. Winter kill from snow mold requires a much less extreme treatment than botrytis blight or excessive thatch.
Remove patches of winter-killed or dog-damaged grass with a rigid-tined garden rake. If only the dead grass pulls away, all you need to do is over-seed thin areas. If all of the grass pulls away like a toupee, get the soil tested for fungus or viruses before reseeding.
Rent a core aerator to break up thick layers of thatch or lawns that have compacted soil. Core aerators are heavy machines that operate like lawn mowers; aerate one way and then run the machine at right angles to the original lines for complete coverage. Aerating punches hundreds of small holes in the surface for air and water to get to grass roots.
Use a thatching rake, called a power rake, to pull thatch out of the lawn. Thatch rakes have hooked, sharp steel tines that cut, or “scarify” the ground as they pull all of the dead grass out of the lawn. Thatching strips the dead grass that protects grass roots as well as destroying grass crowns; reseeding is often necessary.
Water your lawn well afterward, no matter what method you use to remove dead grass. It stimulates roots and helps undo the damage done by thatching.
Things You Will Need
- Metal broom rake
- Garden rake
- Thatching or power rake
- Core aerator
- Baskets or garden cart
- Bleach or rubbing alcohol
- To minimize snow mold, vole damage and other over-winter problems, mow your lawn at its recommended height as late in the fall as possible and use a broom rake to spread out piles of melting snow in the spring.
- Clean tool tines with a solution of water and 50 percent bleach or 70 percent rubbing alcohol to avoid the spread of bacteria and viruses.
- If you have to remove large quantities of dead grass or must thatch your lawn more than every few years, get your soil tested at your local state university agricultural or USDA extension; you might need organic amendments to lighten a clay soil or lime or sulfur to adjust the pH of the soil.
- Don’t remove the beneficial layer of grass clippings and organic matter that helps insulate roots and provide nutrients. Thatch is a buildup of dead grass and organic matter that forms a hard watertight barrier; it does not need to be removed unless it exceeds half an inch in depth.
- Never add grass removed from areas infected with diseases or fungus in your compost pile; the heat of the heap will protect them from freezing temperatures and facilitate their spread as you use the compost.
- Core aerators and mechanical thatchers are both labor-saving devices but both are heavy machines that require strength and skill to use. Be sure you get complete instructions and a demonstration before renting or buying one of these machines.