How to Build Raised Beds | A Weekend Project for Better Soil

Build a raised bed by assembling a level frame no more than four feet wide, then fill it with a quality soil mix and let it settle before planting.

For the full breakdown, see our best Custom Raised Beds guide.

For most home gardens, the practical baseline for how to build raised beds comes down to a rectangular frame set on level ground, filled with a soil blend that drains well. The payoff is real: warmer soil in spring, better drainage, and no more fighting compacted ground. The sweet spot for DIY is a bed about four feet wide or less, so the center stays within reach from either side. Most vegetables need roughly ten inches of soil to thrive, which means a single layer of lumber often does the job.

Choose the Right Spot and Call 811 First

Start with location. Pick a spot that gets full sun — most vegetables want six to eight hours of direct light daily. Before you dig anything in the U.S., call 811 to have underground utilities marked. That one call costs nothing and can save you from hitting a gas line or buried cable.

Clear the area of grass and weeds. You can dig out the sod or smother it with cardboard a few weeks ahead. Level ground matters more than people expect — a bed that sits unevenly will settle lopsided and drain poorly.

Cut the Lumber and Assemble the Frame

Using 2×6 lumber is the standard move.

• Wear safety goggles, a dust mask, and work gloves when cutting.
• Lay the first layer and check it’s level both horizontally and diagonally.
• Screw the timbers together at each corner with heavy-duty coach screws.
• If you stack more than one layer, overlap the joints and add vertical battens inside the corners for stability.
• Attach hardware cloth to the bottom to keep burrowing animals out, then line the inside with plastic sheeting.

For a single-layer bed, set the frame directly on the cleared ground. For deeper beds over 20 inches, the RHS recommends removing the turf and topsoil underneath, then filling the base with rubble or subsoil to improve drainage without wasting good soil above.

What Soil Mix Goes In a Raised Bed?

The fill matters as much as the frame. You can adjust the blend for what you’re growing; root crops appreciate a bit more sand, while leafy greens like extra compost.

Fill the bed to about 2 inches below the rim. That gap gives the soil room to settle after watering and rain. Firm it down gently as you go, but don’t compress it into concrete. Let the bed settle for a couple of weeks before sowing or planting, so the soil structure has time to stabilize.

If you want to skip the math and the build, ready-made options save a weekend.

Common Mistakes That Ruin a Raised Bed

These are the errors that come back to bite you months later:

• Going too wide. Anything over four feet forces you to step on the soil to reach the middle, which compacts it.
• Skipping the level check. An uneven bed settles lopsided and creates dry and soggy zones.
• Blocking drainage. A solid plastic liner with no holes turns your bed into a bathtub after heavy rain.
• Filling to the brim. No room for settling means soil spills over the edges and roots get exposed.
• Forgetting 811. In the U.S., this is the step people skip until they hit something expensive.

One thing to note on materials: rot resistance matters, but no single “best” material works for every garden. Cedar and composite lumber last longest; untreated pine is cheapest but rots in a few years. Treated lumber is fine for edibles — the copper compounds used today don’t leach into soil at harmful levels, according to general consensus among extension services.

For drainage in deep beds, the RHS recommends removing turf and the underlying topsoil, then replacing it with rubble or subsoil. This cuts the volume of good soil you need and stops water pooling at the bottom.