Topsoil

Topsoil is the top six to ten inches of native soil, stripped, stockpiled, then run through a shaker screen to pull out roots, rock, sticks and construction debris. What comes off the belt is dark, loose and consistent, so it rakes flat and does not leave hard clods sitting under new sod.

We screen ours at a half inch. That is fine enough to seed into directly and coarse enough that it still drains — an important balance on the Gulf Coast, where a soil that is too fine turns to a sealed crust after the first hard August rain.

Screened topsoil is not the same product as fill dirt, and the two are not interchangeable. Topsoil carries organic matter and biology, which is exactly what makes it grow things and exactly what makes it a poor structural fill. Anything load-bearing should sit on fill dirt or base rock instead.

For a new lawn from seed, plan on three to four inches of topsoil over a graded subsoil. For sod, two to three inches is plenty as long as the pad underneath is already shaped and firm. For patching low spots, match the surrounding grade and feather the edges so you do not leave a visible shelf.

One cubic yard covers 324 square feet at one inch deep. A 1,500 square foot front yard at two inches is roughly nine to ten cubic yards, which lands comfortably inside one tandem dump load.

Always order to the next whole yard. A second delivery for two short yards costs far more than the material you rounded up on.

Spread with a landscape rake in lifts of no more than two inches, working from the far side of the pile back toward the driveway so you are never hauling across finished ground. Water lightly between lifts to settle the material rather than compacting it with a roller — topsoil that is packed hard will not let roots through.

Expect ten to fifteen percent settlement over the first month. If you are levelling to a fixed edge, such as a patio or a sidewalk, build a touch high and let the rain bring it down.

Houston-area yards sit on heavy gumbo clay that swells when wet and cracks when dry. Laying topsoil straight over untouched clay creates an interface layer where water perches and roots stop. Scarify the clay two or three inches with a tiller or a box blade before the topsoil goes down, or blend a couple of inches of sandy loam in at the boundary.

In low-lying neighborhoods near the bay, check your drainage plan before adding soil depth. Raising a yard without a swale or a French drain simply pushes water onto the fence line — and onto your neighbor.