What You Need to Know Before You Start

A pallet raised bed costs almost nothing if you can find free pallets, takes a weekend to build, and gives you a garden bed 3 to 4 feet off the ground. You stack four pallets into a square or rectangle, find the corners with bolts or brackets, add landscape fabric to the bottom, and fill it with soil. The whole job takes 2 to 4 hours depending on how many pallets you're stacking and whether you reinforce the corners.

The catch is that not all pallets are safe to use. Pallets stamped with HT (heat-treated) are fine for vegetables. Pallets stamped with MB (methyl bromide) were treated with a pesticide and should not go near food gardens. If there's no stamp, assume it's unsafe and skip it. You also need to inspect each pallet for rot, deep cracks, or nails sticking out—these create weak spots and safety hazards.

Key Takeaways

  • Only use pallets stamped HT (heat-treated); pallets marked MB or with no stamp may contain pesticides unsafe for food gardens.
  • A four-pallet bed takes four corner brackets or eight bolts, landscape fabric, and 2 to 3 cubic yards of soil to fill completely.
  • Inspect every pallet for rot, cracked boards, and protruding nails before assembly, and sand or remove any nails that stick out.
  • Bolts through the corners hold better than nails or screws, especially if you plan to keep the bed for more than one season.
  • Line the bottom with landscape fabric to block weeds and prevent soil from washing away, but leave drainage holes or gaps so water doesn't pool.

Finding and Inspecting Pallets

Free pallets come from warehouses, garden centers, grocery stores, and shipping companies. Call ahead and ask if they have pallets they're throwing away—most places are happy to have someone haul them off. You need four pallets of the same size for a square bed, or three to five if you're building a rectangle. Standard pallets are 40 inches by 48 inches, which makes a bed roughly 4 feet by 4 feet or 4 feet by 8 feet depending on how you arrange them.

Before you take a pallet home, check the stamp on the bottom. Look for HT in a circle—that means heat-treated and safe for food. If you see MB, that's methyl bromide, a pesticide. Walk away. If there's no stamp at all, don't use it in a vegetable garden. Once you have safe pallets, lay them flat and look for soft spots, deep splits in the wood, or boards that are warped so badly they won't sit flat. Press your thumbnail into the wood—if it dents easily, the pallet is rotting and won't hold soil weight. Also check for nails sticking out more than a quarter inch. You can hammer these flush or pull them out with a pry bar.

Gathering Tools and Materials

You need a drill, a wrench or socket set, a level, and a hammer or pry bar. For fastening, choose either four corner brackets (L-shaped metal pieces bolted to two pallets at each corner) or eight bolts (two per corner, drilled straight through the wood). Bolts are stronger and cheaper—a pack of eight 3/8-inch bolts with washers and nuts costs $10 to $15. Corner brackets run $20 to $40 for a set of four. You'll also need landscape fabric (a roll costs $15 to $25 and covers multiple beds), a staple gun with staples, and soil.

For soil, calculate volume by multiplying length × width × depth in feet, then divide by 27 to get cubic yards. A 4-by-4-foot bed filled 12 inches deep needs about 1.8 cubic yards. A 4-by-8-foot bed needs 3.6 cubic yards. Soil delivered costs $40 to $80 per cubic yard depending on your region; bagged soil from a garden center costs more per yard but works if you're filling a small bed. Buy a mix labeled "garden soil" or "raised bed mix"—not pure compost, which compacts, and not pure topsoil, which drains too fast.

Assembling the Frame

Lay all four pallets on flat ground in the shape you want—a square or rectangle. Use a level to check that the ground is reasonably flat; if one corner is more than an inch lower than the others, dig out soil or add soil under the low corner until the pallets sit level. This matters because uneven pressure will cause the frame to twist and the bolts to loosen over time.

If you're using bolts, drill two holes through the corner where two pallets meet, one hole about 4 inches from the top and one about 4 inches from the bottom. Drill straight through both pallets at once so the holes line up. Use a 3/8-inch drill bit. Slide a bolt through each hole, add a washer and nut on the back side, and tighten with a wrench until snug—don't over-tighten or you'll crack the wood. If you're using corner brackets, bolt one bracket to the inside corner of each pair of pallets, using the bolt holes already in the bracket.

Once all four corners are bolted, check the frame with a level in both directions. The top should be level or very close. If one side is high, loosen the bolts on that corner slightly, tap the frame with a hammer until it's level, then re-tighten. This takes patience but saves you from a lopsided bed that sheds soil.

Lining the Bottom and Adding Soil

Lay landscape fabric across the bottom of the frame, stapling it to the inside of the pallets every 6 inches or so. The fabric blocks weeds from growing up through the bottom and keeps soil from washing out between the pallet boards. However, don't seal the entire bottom—leave gaps or poke drainage holes every foot or so, or water will pool and rot the pallet wood. A straightforward approach is to staple the fabric loosely so water can seep out the sides.

Once the fabric is in place, fill the bed with soil. Pour it in and rake it level. The soil will settle over the first week or two, so fill it slightly above the rim of the pallets—it will drop to the rim level as it compacts. Water the soil thoroughly after filling; this helps it settle and tells you whether drainage is working. Water should soak in within a few minutes. If it pools on top, you either have poor drainage or the soil is compacted too much.

Reinforcing Corners for Long-Term Use

Pallets are not designed to hold weight on all four sides at once. Over one or two seasons, the corners will start to sag or the bolts will loosen as the wood shifts. If you want the bed to last three years or more, add extra support. The simplest method is to drive a 2-by-4 post into the ground at each corner, inside the frame, and bolt the pallets to the post. This transfers the weight to the ground instead of relying on the bolts alone.

Another option is to add a second layer of pallets on top of the first, offset by 90 degrees (so the boards run perpendicular). This doubles the height and distributes weight more evenly. Bolt the two layers together at the corners. A two-layer bed is 8 to 10 inches tall instead of 4 to 5, which is easier on your back when planting and weeding.

Common Mistakes and How to Avoid Them

Using untreated or MB-stamped pallets: This is the biggest mistake. Untreated wood may have been exposed to pesticides or fuel. MB-stamped pallets are actively toxic. Stick to HT-stamped pallets only, or use new untreated lumber if you're unsure about the source.

Skipping the level check: An unlevel frame will cause one corner to sink faster than the others, cracking bolts and warping the wood. Spend five minutes getting it level before you fill it.

Filling with pure compost or potting mix: These are expensive and drain too fast. Use a blend of topsoil, compost, and peat moss or coconut coir in roughly equal parts. This holds moisture and nutrients without compacting.

Not securing the corners strongly enough: Nails and screws work for one season. Bolts or brackets last much longer. If you're building a bed you plan to keep, use bolts.

Sealing the bottom completely: Landscape fabric is good; a plastic sheet is not. Plastic traps water and rots the wood. Fabric blocks weeds but lets water drain.

Frequently Asked Questions

Can I use pallets that have been sitting outside for a while?

Only if they're not rotting. Press your thumbnail into the wood in several spots. If it dents easily or the wood is soft, the pallet is too far gone. Pallets that are weathered but still hard are fine—they'll last several more seasons. Check the stamp first; if it's HT, it's safe regardless of age.

How deep should a pallet bed be?

Most vegetables do well in 10 to 12 inches of soil. Shallow-rooted crops like lettuce and spinach can get by with 8 inches. Deeper crops like tomatoes, carrots, and potatoes need 12 to 18 inches. A single pallet is about 5 inches tall, so a two-pallet bed gives you 10 inches, which works for most gardens.

Do I need to treat the wood with anything?

No. Untreated wood will weather and eventually rot, but that takes several years. If you want to extend the life, you can paint the outside with a non-toxic wood stain, but don't use pressure-treated lumber or chemical sealers—these can leach into the soil. Plain wood is safest for vegetables.

What if the ground where I want to put the bed is not level?

Dig out soil from the high spots and fill in the low spots until the ground is reasonably level—within an inch across the whole bed. If the ground is very sloped, you can build a retaining wall on the downhill side using extra pallets or boards, but this is more complex. For most yards, leveling the ground takes 30 minutes and saves hours of trouble later.

Can I move a pallet bed once it's filled with soil?

Not easily. A 4-by-4-foot bed filled with soil weighs 1,500 to 2,000 pounds. If you think you might move it, build it on a wheeled platform or use a single layer of pallets instead of two. Otherwise, plan to leave it where you build it.