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HarvestBench

Guide

How to Prepare a Raised Bed

Pick a sunny, reasonably level spot, set the frame, fill it with a real soil mix, water to settle, and mulch. Skip the rock layer at the bottom.

Updated 2026-08-26

1. Choose the site

Most fruiting vegetables want 6–8 hours of direct sun. Note afternoon shade in hot climates — a little can reduce sunscald on tomatoes and peppers. Keep beds within a hose length of a spigot. A beautiful bed you cannot water will fail in July.

Level the ground under the frame. A bed that sits 3 inches high on one corner will erode mix out of the low side. You do not need a surveyor; a 4-foot level on the boards is enough.

2. Decide what goes under the bed

  • On lawn: you can sheet-mulch with cardboard (tape and glossy labels removed) and set the frame on top. Grass under a filled bed usually dies.
  • On soil: open bottom is best so roots and water can move.
  • On a patio: use a bed with a drainage-safe floor and a mix that drains. Protect the paving from stains if that matters to you.

3. Fill in lifts

Add mix in 4–6 inch layers and water each layer. This removes air pockets without compacting the bed into concrete. Use the soil calculator so you are not short on the last wheelbarrow.

4. Settle, then top off

After a thorough watering, the surface will drop. Top off to within an inch of the rim, leaving space for mulch. You can plant the same day in a compost-based mix. If you used a lot of fresh manure compost, wait and check for heat or a strong ammonia smell first.

5. Watering setup

Lay a soaker hose or drip line before mulch if you can. See drip irrigation for raised beds or the soaker hose buying guide for hardware, and how often to water raised beds for scheduling.

Frequently asked questions

Do I need landscape fabric under the bed?

Usually no, on soil. Fabric can block roots and become a weed-root nightmare at the edges. Use cardboard if you need a short-term grass barrier.

Should I add fertilizer when I fill the bed?

If the mix already includes substantial compost, you may not need granular fertilizer at fill time. A soil test is the honest way to decide. See the fertilizer guide before broadcasting a high-nitrogen product.