Raised beds with legs sit high enough to garden from a standing or sitting position, and you can build one in a weekend with basic tools and lumber

A raised bed with legs is a wooden box mounted on a frame so the soil sits 24 to 36 inches off the ground. You build it by cutting four boards for the sides, four posts for the legs, and a base frame, then fastening them together with screws or bolts. The whole structure takes a day or two and costs between $60 and $150 in materials, depending on wood type and size. The main advantage is that you never bend to ground level — you can garden from a chair or standing upright — and the legs keep the bed away from tree roots and poor soil below.

Key Takeaways

  • A raised bed with legs needs four corner posts (usually 4x4 lumber), four side boards, and a base frame to sit on the ground.
  • Cedar, composite, or untreated pine all work; avoid pressure-treated wood if you are growing vegetables, because the chemicals can leach into soil.
  • Screw the boards to the posts with 3-inch deck screws, and bolt the base frame to the legs so the whole structure stays square and stable.
  • A 4-by-8-foot bed with 12-inch-deep sides holds about 32 cubic feet of soil and costs roughly $100 to $150 in materials.

Choose your wood and measure the footprint

Start by deciding how long and wide you want the bed. A 4-by-8-foot rectangle is standard because it fits two rows of plants and lets you reach the center from either side without stepping in. You can go smaller (3 by 6 feet) or larger (4 by 12 feet), but anything wider than 4 feet becomes hard to reach across. Write down your final dimensions — you will need them to cut the boards and posts.

Next, pick your wood. Cedar lasts 10 to 15 years and resists rot naturally, but costs $2 to $4 per board foot. Composite (wood fiber mixed with plastic) lasts 20+ years and never rots, but runs $3 to $6 per board foot and is heavier to move. Untreated pine costs $0.80 to $1.50 per board foot but rots in 5 to 7 years. Avoid pressure-treated wood for vegetable beds — the chemicals used to preserve it can leach into soil. For a 4-by-8 bed, you will need about 32 linear feet of boards (four 8-foot boards and four 4-foot boards for the sides).

Cut the posts and boards to length

The four corner posts should be 4x4 lumber, cut to a height that puts the top of the bed at your preferred working level. Most people choose 24 to 30 inches above ground. If you want the bed 28 inches high and the side boards are 12 inches deep, cut the posts to 40 inches (28 inches above ground plus 12 inches buried or sitting on the base frame). You can adjust this later if needed.

Cut the side boards to your footprint dimensions. For a 4-by-8 bed, cut two boards to 8 feet and two to 4 feet. If your boards come longer than you need, use a circular saw or hand saw to cut them square. Sand any rough edges with 80-grit sandpaper so they do not splinter when you handle them.

Build the base frame and attach the legs

The base frame sits on the ground and keeps the legs from sinking into soft soil. Cut four pieces of 2x6 or 2x8 lumber to form a rectangle matching your bed footprint — two pieces at your length and two at your width. Lay them flat on the ground in a rectangle, then bolt the corners together with 1/2-inch bolts and washers. Drill a hole through both boards at each corner, slide the bolt through, and tighten the nut on the underside. This base frame does not need to be pretty, but it must be square — measure corner to corner diagonally; both measurements should be equal.

Stand the four corner posts upright at each corner of the base frame and bolt them to the frame with two 1/2-inch bolts per post, one near the top and one near the bottom. Drill the holes before you bolt, and use washers under both the bolt head and the nut so they do not pull through the wood. Check that each post is plumb (perfectly vertical) with a level before you tighten the bolts all the way.

Attach the side boards to the posts

Stand the four side boards on edge and position them against the inside of the posts. The top of each board should align with the top of the posts. Drill pilot holes (small holes that guide the screw) through the board into the post, then drive 3-inch deck screws through the board into the post. Use two screws per corner — one near the top and one near the bottom. This keeps the board from twisting as you tighten the screws.

Work your way around the bed, screwing each board to its two corner posts. Check that the boards sit flush against the posts and that the top edges are level. If one corner is higher than the others, loosen the bolts at the base frame, adjust the post height, and re-tighten. Once all four boards are screwed in place, the bed should be rigid and square.

Reinforce the corners and add a liner if needed

If the bed will hold heavy, wet soil (which can push the sides outward), add corner braces. Cut four pieces of 2x4 lumber to 12 inches and bolt one diagonally across each inside corner, connecting the post to both adjacent boards. This is optional for small beds but worth doing if you are building something larger than 4 by 8 feet.

If you are concerned about wood chemicals leaching into soil (even with untreated wood), line the inside bottom and sides with landscape fabric or a pond liner. Staple it to the inside of the boards and trim the excess. This is not necessary but adds a barrier between the wood and the soil. Do not use plastic sheeting — it traps water and causes rot.

Fill the bed and check for stability

Before you add soil, walk around the bed and push on each side to make sure it does not flex or wobble. If it moves, go back and tighten all the bolts and screws. Once it feels solid, fill it with soil. A 4-by-8-foot bed that is 12 inches deep needs about 32 cubic feet of soil — roughly 1.2 cubic yards. You can buy bagged soil or have a landscape supplier deliver bulk soil. Fill it to within an inch of the top so water does not spill over the edge.

Let the soil settle for a few days before you plant. If it sinks noticeably, add more. The bed is now ready to use and should last 5 to 20 years depending on your wood choice.

Frequently Asked Questions

Can I use 2x12 boards instead of 4x4 posts?

Yes. You can build a simpler frame by stacking 2x12 boards at the corners and bolting them together instead of using separate posts. This works for beds up to 4 feet wide, but taller beds (over 18 inches) need the post-and-board design because the boards alone will bow outward under soil pressure.

How deep should the bed be?

Most vegetables need 12 inches of soil minimum; root crops like carrots and beets need 18 inches. Shallow beds (8 to 10 inches) work for lettuce and herbs. Deeper is always better if you have the space and budget, because it gives roots more room and holds more water.

Do I need to treat the wood with sealant?

Cedar and composite do not need sealant. Untreated pine will last longer if you brush on a non-toxic wood stain or sealant, but it will still rot eventually. Never use pressure-treated wood sealant on a vegetable bed.

What if the ground is uneven?

Level the ground as much as you can before you set the base frame. If the slope is gentle, you can shim the base frame with shims or gravel until it is level. If the slope is steep, build the bed on a level terrace or accept that one side will sit lower than the other.

Can I move the bed once it is built?

A full bed is very heavy — 32 cubic feet of soil weighs about 1,600 pounds — so moving it is difficult. Build it where you want it to stay. If you need to move it later, drain the soil into buckets, unbolt the frame, and reassemble it in the new location.