Yes, putting soil on grass works well when you do it right with thin layers. Apply only one-quarter to one-half inch (0.6 to 1.3 cm) at a time. Any thicker and you risk smothering your grass and killing the very lawn you are trying to improve.
I learned this lesson the hard way with my first topdressing lawn project. I dumped a thick layer of topsoil over a bumpy section thinking it would level out fast. The grass under that heavy layer died within two weeks. I had to reseed the whole area and start over. Now I apply thin coats over several seasons instead of one thick layer.
The technique works because grass blades can push through thin soil layers and keep growing. Thicker layers block light and air from reaching the crown where new growth starts. Once you smother that crown, the plant dies and you end up with bare dirt instead of improved turf.
Adding soil to lawn areas brings several benefits when done right. It levels out bumps and low spots over time through repeated thin applications. The organic matter in compost improves your existing soil structure and drainage. Topdressing also helps grass seed make better contact with soil when you overseed in fall.
Choose your topdressing material based on what your lawn needs most. Screened compost works great for adding nutrients and organic matter to poor soils. A sand and compost blend helps level uneven lawns without adding too much nitrogen. Pure sand suits lawns with heavy clay soil that needs better drainage. Avoid topsoil from unknown sources since it often contains weed seeds.
Fall after aeration gives you the best window for soil over grass projects. The holes left by aeration let your topdressing drop down into the root zone. Grass grows strong in fall and recovers fast from the stress. Spring works as a backup timing but weeds compete harder for any bare spots you create.
I tested different application methods on my own lawn over three seasons. The best results came from using a shovel to drop small piles across the lawn, then spreading with a leaf rake in a back-and-forth motion. Work the material into the grass until you can barely see it. You want the blade tips showing through the top.
Plan for multiple rounds if you have deep low spots or severe bumps. One application levels your lawn by about half an inch at most. Wait at least a month between applications so grass can recover and grow through each layer. Three thin rounds spread over a year or two beats one thick layer that kills your turf. Patience with topdressing lawn projects pays off with lasting results.
Read the full article: Complete Lawn Care Schedule for Every Season
