How to Build and Fill a Raised Garden Bed

Size it for reach and roots

• Width: 3-4 ft if reachable from both sides; ~1.5-2 ft if only one side is accessible.
• Length: up to about 8-12 ft is easy to manage.
• Depth: 6+ inches for leafy greens/herbs; 12-18 inches for tomatoes, squash, and other deep rooters.

Build and fill

1. 1Pick a sunny, level spot — Most vegetables want 6+ hours of sun; level ground keeps water even.
2. 2Frame it — Wood, stone, or galvanized steel — set the frame on soil (not sealed pavement) so water drains through.
3. 3Fill with a soil + compost blend — A common fill is about half quality topsoil and half compost/organic matter for fertility and structure.
4. 4Top up yearly — Beds settle as organic matter breaks down — add compost each season.

→ Need a fill quantity? Use the GardenSays soil/raised-bed volume calculator to turn your bed's dimensions into cubic feet or bags.

Sources

Reviewed 2026-07-18. We cite university Extension, government, and established horticultural sources — and never invent pesticide rates or dangerous treatments.

• Iowa State University Extension — Creating Raised Bed Planters — Keep raised beds narrow enough to reach the center (about 3-4 ft), any convenient length, and deep enough for the crop; fill with a blend of topsoil and organic matter/compost with good drainage.
• University of Minnesota Extension — Raised bed gardens — Size raised beds so the center is within reach; most vegetables need at least 6-12 inches of rooting depth; fill with a quality soil and compost mix.

Keep going