Mulch Calculator

For standard weed prevention and moisture retention, a depth of 2 to 3 inches is ideal. If you are just refreshing existing mulch, a thin 1-inch layer is enough. Avoid going deeper than 4 inches, as it can block oxygen from reaching plant roots.

Bulk mulch is sold by the cubic yard and is almost always cheaper for large areas (over 2 cubic yards). However, bagged mulch is much easier to transport in a standard car and allows you to work in stages without a giant pile sitting in your driveway.

Since a cubic yard equals 27 cubic feet, it takes exactly 13.5 bags of 2 cubic feet mulch, or 9 bags of 3 cubic feet mulch, to make up a full yard.

Shredded wood and bark mulches decompose over time. You should expect to add a fresh 1-inch top-dress layer once a year—usually in mid-spring—to keep weed protection active and restore color.

No, you do not need to remove old mulch unless it has developed mold, disease, or has become too thick (exceeding 4 inches). Simply break up any hard, matted crust on the old mulch with a rake before spreading the new layer.