How Much Topsoil is Needed to Plant a New Lawn?

Recommendations

• To start a new lawn, about 4 inches of quality topsoil will be required. This amount promotes healthy root growth, says Judy Pray in "Garden Wisdom & Know-How." In his book "Turfgrass Maintenance Reduction Handbook", Doug Brede recommends 4 to 6 inches of topsoil as a standard for lawns.

Benefits

• Topsoil is rich in organic matter that makes soil porous for better air and water circulation to the roots. The higher level of nutrients in the soil work like slow-release fertilizer for the plants. There are fewer problems with compaction and layering in topsoil as compared to poorer quality soils.

Alternatives

• The best way to determine if you need to add topsoil before starting a lawn is to get a soil test performed. If your existing ground in rich is loam, no topsoil will be needed, writes Jerry Baker in "Jerry Baker's Green Grass Magic." Economical alternatives to topsoil include the addition of appropriate quantities of lime, compost and fertilizer to existing ground, as determined by the soil test.