Build a basic raised bed in a weekend with wood, screws, and a drill

A raised bed is a wooden or composite box you fill with soil and plant into. The simplest version takes four boards, four corner brackets, and a drill — you can assemble one in two to four hours. The boards sit on the ground (no foundation needed for most yards), you attach them at the corners, and you fill it with soil. No digging, no tilling, no fighting existing ground.

The most common size is 4 feet by 8 feet by 12 inches tall, which fits standard soil bags and lets you reach the middle from either side. You can build smaller (3 by 6 feet works for tight spaces) or taller (18 inches reduces bending). The material you choose — untreated wood, composite boards, or galvanized metal — affects cost, durability, and how long the bed lasts before it needs replacing.

Key Takeaways

  • Untreated cedar or composite boards last 10 to 15 years; pressure-treated wood lasts longer but costs more and was historically treated with chemicals (modern versions are safer, but cedar remains the preference for vegetable gardens).
  • A 4-by-8-foot bed 12 inches tall requires eight 8-foot boards (or four 8-foot and four 4-foot), four corner brackets, 16 to 20 screws, and roughly 32 cubic feet of soil.
  • You do not need a foundation, concrete, or leveling tools — a level and a drill are the only power tools most people need.
  • Composite boards cost two to three times more than wood but do not rot, splinter, or need staining, and they last 20+ years.

Choose your material: wood, composite, or metal

Untreated cedar is the standard choice for vegetable gardens. It resists rot naturally, costs $2 to $4 per linear foot, and lasts 10 to 15 years before the wood begins to break down. You can stain it to extend life, but stain is optional. Cedar is lightweight, straightforward to cut, and widely available at home centers.

Pressure-treated wood lasts 15 to 20 years and costs $1.50 to $3 per linear foot — cheaper than cedar. Modern pressure-treated lumber (made after 2004) uses copper-based preservatives, not arsenic, and is safe for vegetable gardens. The trade-off is that it is heavier, harder to cut by hand, and many gardeners prefer to avoid it for food crops even though the risk is low.

Composite boards (wood fiber mixed with plastic) cost $4 to $8 per linear foot but do not rot, splinter, or need maintenance. They last 20+ years and look finished without staining. They are heavier than wood and harder to cut, so you may need a power saw. Composite is the best choice if you want to set the bed and forget it.

Galvanized steel or aluminum raised beds come as kits and cost $150 to $400 for a 4-by-8 bed. They last indefinitely, take 30 to 60 minutes to assemble, and require no tools beyond a wrench. The downside is that metal conducts heat and can warm the soil too much in hot climates, and they are not as straightforward to customize as wood.

Gather materials and tools

For a standard 4-by-8-foot bed 12 inches tall, you need four 8-foot boards (or two 8-foot and four 4-foot boards if you are building two 4-by-4 beds). If you choose wood, ask the home center to cut boards to length — most will do this free or for a small fee. Composite and pressure-treated boards are often available pre-cut.

You also need four corner brackets (L-shaped metal or composite brackets that bolt or screw the boards together), 16 to 20 exterior-grade wood screws (3-inch screws for wood, 2.5-inch for composite), and a power drill with a screwdriver bit. A level is helpful but not essential if your yard is already fairly flat. A tape measure, pencil, and work gloves round out the list.

For soil, a 4-by-8-foot bed 12 inches tall holds about 32 cubic feet. Most garden centers sell soil in cubic yards (27 cubic feet per yard), so you need roughly 1.25 cubic yards. You can also buy bags — a standard bag is 2 cubic feet, so you would need 16 bags. Bulk soil is cheaper per cubic foot but requires delivery; bags are more expensive but easier to handle if you do not have a truck.

Assemble the frame on level ground

Lay the four boards on the ground in a rectangle where you want the bed to sit. The spot does not need to be perfectly level, but avoid low spots where water will pool. If the ground is very uneven, you can level it by removing high spots with a shovel, but most yards are close enough that you can skip this step.

Attach the corner brackets to the inside of each corner. Most brackets have two bolt holes or screw holes — one on each board. Drill pilot holes first (a smaller hole that guides the screw and prevents splitting), then drive the screws. Tighten all four corners, then use a level to check that the frame sits flat. If one corner is high, you can shim it with a shingle or a flat stone underneath.

If you are using composite or pressure-treated boards, use stainless steel or galvanized screws — regular steel screws will rust and stain the boards. For cedar, galvanized or exterior-grade screws work fine. Do not use interior drywall screws; they will rust and fail.

Fill with soil and let it settle

Once the frame is assembled and level, fill it with soil. If you ordered bulk soil, have it delivered and shovel it into the bed. If you are using bags, open them and pour the contents in. Do not compress the soil as you fill — let it settle on its own over the first week or two. The soil will compact naturally as you water and plant.

Water the soil thoroughly after filling. It will sink an inch or two as it settles. You can add more soil after a few days if needed. Most gardeners fill the bed to about 1 inch below the rim so water does not spill over when they water.

If you are planting when ready, you can start with seeds or transplants right away. If the soil is very new and dense, it may take a season to develop structure and drainage, but most store-bought garden soil is ready to plant into the same day.

Extend the life of wood beds with straightforward maintenance

Cedar and untreated wood beds will eventually rot at the base where the wood touches the ground. You can slow this by staining the outside with an exterior wood stain every two to three years. Do not use paint — it traps moisture and speeds rot. Stain is optional; many gardeners skip it and replace the bed after 10 to 15 years.

You can also line the inside bottom with landscape fabric or hardware cloth (a metal mesh) to keep soil from touching the wood directly. This is not necessary but can add a few years to the bed's life. Landscape fabric alone does not stop rot; hardware cloth (which keeps burrowing pests out) is more effective.

Pressure-treated beds need no staining and require almost no maintenance. Composite beds need none at all — just rinse them off if they get dirty.

Build multiple beds or customize the size

If you want more than one bed, you can build them side by side or in a row. Leave at least 2 feet between beds so you can walk and work. A 3-by-6-foot bed uses the same method and requires six 6-foot boards, four brackets, and 16 cubic feet of soil. An 18-inch-tall bed (good for people who have trouble bending) uses the same footprint but requires taller boards and more soil.

You can also build L-shaped or tiered beds by connecting multiple frames, though this requires more brackets and planning. Start with one standard bed to learn the process, then expand once you see how it works in your yard.

Frequently Asked Questions

Do I need to put anything on the bottom of the raised bed?

No. Soil drains directly into the ground below, which is fine for most plants. If you want to keep burrowing pests (moles, voles) out, lay hardware cloth on the ground before filling. Landscape fabric alone does not stop determined pests but can slow soil from washing into the ground.

How deep does a raised bed need to be?

Twelve inches works for most vegetables, herbs, and shallow-rooted plants. Carrots, beets, and potatoes need 12 to 18 inches. Lettuce and spinach need only 6 to 8 inches. If you are growing in a very hot climate, deeper beds (18 inches) keep roots cooler. Shallow beds (6 inches) work for herbs and greens but limit what you can grow.

Can I use treated wood for a vegetable garden?

Modern pressure-treated wood (post-2004) is safe for vegetables. It uses copper-based preservatives, not arsenic. Cedar is still preferred by many gardeners because it looks better and feels safer, even though the risk from treated wood is very low. The choice is yours; both work.

How much does it cost to build a raised bed?

A 4-by-8-foot cedar bed costs $80 to $150 for materials (boards, brackets, screws), plus $40 to $80 for soil if you buy bags, or $30 to $50 if you order bulk. Composite costs $200 to $300 for materials plus soil. A metal kit costs $150 to $400 total. Labor is zero if you build it yourself.

Can I build a raised bed on concrete or pavement?

Yes, but drainage is poor — water sits in the soil instead of draining into the ground. You can drill holes in the bottom boards or use a raised bed with a built-in drain, but most gardeners prefer to place beds on soil or grass where drainage happens naturally. If you must use concrete, add a drain layer (gravel or sand) at the bottom of the bed.