Good topsoil is loose, well-draining and full of organic matter. Without it, plants fail to thrive.Topsoil is often missing from a newly constructed home's yard; construction crews may have carted it away during the construction process. Topsoil may be absent entirely from rocky, mountainous home sites. Plan to add at least 6 inches of topsoil to very hard, poor sub soils.
One yard of topsoil will cover 324 square feet of soil, spread at a depth of 1 inch, or 100 square feet of soil spread at a depth of 3 inches. To calculate how much topsoil you'll actually need, multiply the number of square feet in the area by the number of inches of topsoil you want to install. Divide that number by 324. For example, if the space is 500 square feet and you want to install 6 inches of topsoil, the equation would like like this: 500 x 6 = 3,000, divided by 324 = 9.2 yards of topsoil.
To figure the square footage of your area, measure the width and length of the space. Add a few extra feet for irregular, curved areas. Multiply the width by the length to get the square feet.
Before you buy topsoil, inspect it and ask questions. Find out where it came from, if it has been sifted, and if it contains any amendments. Many topsoils are amended with compost or manure, but avoid using topsoil containing biosolids on vegetable gardens. These products may contain heavy metals or chemicals. Moisten the topsoil and squeeze it. Good, loamy topsoil crumbles in your hands. Clay soils become sticky and compacted, while sandy soils feel grainy and dry. Ask for the results of a soil test or test a small amount yourself to determine the pH of the soil and organic matter content. This process may seem unnecessarily labor intensive, but topsoil is a major investment in your yard. Buying good topsoil saves you time and money later because plants grow more quickly and are healthier. The most economical way to buy large quantities of topsoil is in bulk through a landscaping company.
Spread the topsoil over the surface of the yard, removing any rocks or debris as you work. Add 2 to 3 inches of compost or rotted manure to improve the texture and drainage. Till the topsoil and soil amendments into the existing soil to a depth of 8 inches. Rake and allow the soil to settle for at least one week before planting.