🪴 Raised Bed Planning
Find exactly how much soil, compost, and amendments to buy for your raised bed. Supports custom mix ratios and multiple beds.
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The most common mistake is underestimating how much soil a raised bed needs. A standard 4×8 ft bed that's 12 inches deep needs 32 cubic feet of soil — about 16 large bags.
Mel's Mix (Square Foot Gardening): Equal thirds of blended compost, peat moss, and coarse vermiculite. Excellent drainage and nutrition but expensive.
Classic raised bed mix: 60% quality topsoil, 30% compost, 10% perlite or aged bark. Cheaper and works well for most vegetables.
| Crop type | Min depth |
|---|---|
| Lettuce, herbs, flowers | 6 in (15 cm) |
| Most vegetables | 12 in (30 cm) |
| Tomatoes, squash | 18 in (45 cm) |
| Carrots, parsnips | 24 in (60 cm) |