ZONE WORKSHEET
Plan Multiple Landscape Beds
Give every bed its own sketch, area, target depth, material, and allowance; only combine quantities that truly share a product and installation condition.
SHORT ANSWER
The working rule
Create one row per bed or material zone, calculate its net horizontal area after exclusions, multiply by that zone’s finished depth, then add only a named allowance. Combine rows only when the material, depth, and supplier unit are the same.
Use zones that match the install
Separate front beds, tree rings, slopes, vegetable areas, and hardscape edges when their depth, material, access, or installation date differs. A single total can conceal a shallow topping layer beside a deeper new bed.
Sketch each zone with fixed references, included shapes, and exclusions such as boulders, paving, established plant islands, or utility features. Keep shared boundaries on one drawing to avoid double-counting.
Calculate each bed before combining
For example, a 240-square-foot bed at 3 inches needs 240 × 3 ÷ 324 = 2.22 cubic yards before allowance. A separate 90-square-foot ring at 2 inches needs 0.56 cubic yards. Keep the two volumes separate until you confirm they use the same material and delivery unit.
Document why any allowance is needed: uneven grade, settlement, inaccessible edges, bag rounding, or handling loss. It is not a replacement for an unknown boundary or depth.
Close out by material and delivery
Group compatible rows by material, then round to the supplier’s bag, bulk-yard, pallet, or truck increment. Keep compost, bark, stone, soil, and engineered products distinct because their density and placement rules differ.
After installation, sample depth in each bed and record delivered quantity. The closeout becomes a better baseline for next season than an undifferentiated project total.
A practical workflow
- Sketch and name each bed or material zone with its exclusions.
- Calculate net area and depth per zone before applying an allowance.
- Group only like materials and units for ordering, then round to supplier increments.
- Verify installed depths and retain the worksheet for maintenance planning.
Put the method to work
Primary references
- USDA Natural Resources Conservation ServiceMulching conservation practice standard 484
- US Environmental Protection AgencyWaterSense Water Budget Tool
- USDA Natural Resources Conservation ServiceGetting started with Web Soil Survey and Areas of Interest
Reference links were checked during the review shown above. Product instructions, regulations, and site conditions can change; verify the current material before acting.