Can You Put New Dirt & Plants on Top of Dead Grass?

Herbicide

• Spraying an area with an herbicide is a simple way to kill off everything that is growing on the surface, including the root mass below the soil. Herbicides that include glyphosate are post-emergent which means they kill existing plants. Glyphosate is also non-selective and kills every plant it touches, including grass. Follow the manufacturer's directions for the wait time after spraying before you replant. Once the grass is dead, you can replant the area.

Topsoil

• A thick layer of topsoil or mulch often suffocates any plants growing. Since grass is not a deep-rooted plant, 4 to 6 inches of soil over grass usually eliminates the need for spaying with an herbicide. If you do use an herbicide, just a couple of inches of dirt will cover the old grass. The roots of the new plants will reach down through the top layer into the soil below.

Newspaper

• Many gardeners lay down several layers of newspapers over grass before they drop mulch or soil. The newspaper picks up the moisture from the earth and acts as a temporary barrier to weed grass coming through. Over time, the newspaper decomposes into the soil, adding more food matter to the soil for the earthworms and microbes.

Planting

• Once you have addressed the grass and applied your new dirt, you can set your new plants into the garden. Dig a planting hole through the top layer of dirt and through the old grass, large enough to hold the root ball of your plant. Set the plant in the hole and plant is as normal. The roots will feed off the decaying grass and grow easily through the loose soil. Just make sure that you don't plant until after the recommended time if you are using an herbicide.