Which tool fits the job
For a whole job, start with a planner: the garden bed refresh planner for mulch, compost and edging, the new lawn planner for topsoil and seed or sod, and the gravel driveway planner for a driveway in layers. Each draws it to scale and prices it. For one material, the mulch, topsoil, gravel, sand, grass seed and sod calculators give cubic yards, bags, pounds or pallets.
Plan in this order
Measure the area, choose the depth, then convert to what the supplier sells. Bulk material is sold by the cubic yard (27 cubic feet) or the ton, bags by cubic feet or pounds. A 10 × 20 ft bed 3 in deep needs 50 cubic feet of mulch: 1.85 cubic yards, or 25 bags of 2 cu ft.
Common buying mistakes
- Too much mulch. About 3 in after settling is enough for most plants; thicker layers keep the soil too wet. On an old bed, add only the difference, and pull mulch back a few inches from trunks.
- Forgetting settling. Loose topsoil and compost settle, so order about 15% extra. A 4 × 8 ft raised bed filled 12 in deep holds 32 cubic feet; buy about 37.
- Bags for a big job. A cubic yard is 27 bags of 1 cu ft. Past a yard or two, bulk delivery is usually cheaper.
- Assuming every ton is alike. Denser stone covers less per ton, so ask the yard what their cubic yard weighs.
- Seeding too thick or too late. Crowded seedlings compete. Seed cool-season lawns in late summer, sow half the seed each way, cover it ⅛–¼ in and keep the top inch moist.
Call 811 before you dig a driveway base or edging trench so buried utilities get marked.