How Many Bags of Topsoil for a 204 sq ft Flower Bed? Better: Buy Bulk Blend

You’re building a 204 sq ft flower bed, 7 inches deep, for a small tree, flowers, and shrubs. You want to know how many 40-lb bags of topsoil to buy.

Volume Needed

119 cubic feet (4.4 cubic yards). A 40-lb bag of bark-based topsoil is ~1 cubic foot, so ~120 bags. Peat-based bags are heavier, yielding less volume.

Better Alternative

Don’t use bagged topsoil. Find a bulk soil/mulch dealer and buy a blend of mostly native soil mixed with bark, leaf mold, and a little sand. It grows plants better, waters easier, and costs less per cubic yard.