Topsoil & Raised Garden Bed Soil Calculator

1. The Compaction Settling Deficit (15% Shrinkage) Freshly screened and delivered topsoil is heavily aerated. After spreading, walking on it, and two deep watering cycles, the loose soil naturally settles and compacts by 12% to 18%. Ordering only the raw geometric volume guarantees your raised beds or re-graded lawn will finish 1.5 inches below desired grade.

2. Bagged Soil Price Gouging on Large Projects One cubic yard contains 27 cubic feet. A common 1.5 cu ft bag at Home Depot costs roughly $5.50. Buying 18 bags to make 1 single yard costs $99. For a 4-yard lawn project, bagged soil costs roughly $400 in materials plus heavy manual labor, whereas a bulk truck delivery costs $180 total.

3. Ordering Cheap "Fill Dirt" Instead of Screened Topsoil Unscreened "fill dirt" is subsoil excavated from commercial foundation digs, filled with heavy clay clumps, gravel, and weed rootstocks. Topsoil is the organically active upper 6 inches of earth shredded through a 1/2-inch rotating screen. Attempting to plant grass or vegetables in fill dirt suffocates root systems.

4. Over-Tilling and Destroying Soil Aggregate Structure Using a motorized rotary tiller on damp topsoil pulverizes natural soil micropores and macro-aggregates into fine dust. Upon rainfall, this powdered silt consolidates into a concrete-like impermeable crust that repels water and prevents seedling emergence.

5. The "Bathtub Effect" Over Compacted Clay Subgrade Excavating a planting bed into dense native clay and filling it with ultra-porous raised bed mix creates a drainage bathtub. During rainy seasons, water drains rapidly through the topsoil, pools on top of the impermeable clay floor, and rots plant root systems from lack of oxygen. Always rototill 2 inches of compost into the native subsoil boundary.