Build a raised bed in a weekend with basic tools and lumber
An elevated garden bed is a wooden or composite box you fill with soil and plant into. You can build one yourself in four to six hours using a drill, a saw, and four pieces of lumber. The most common size is 4 feet by 8 feet by 12 inches tall, which costs between $40 and $120 in materials depending on wood type. You do not need concrete footings, metal brackets, or special fasteners — a straightforward frame screwed together at the corners works for years.
The basic steps are: cut your lumber to length, drill pilot holes to prevent splitting, screw the corners together, set the frame in place on level ground, and line the bottom if you want to block weeds. Most people finish in one day and plant the same week.
Key Takeaways
- A 4-by-8-foot bed 12 inches tall requires four pieces of lumber (two 8-foot, two 4-foot), a drill with a screwdriver bit, and 16 exterior-grade screws.
- Cedar and redwood last 10 to 15 years; pressure-treated pine lasts 15 to 20 years; untreated pine lasts 3 to 5 years before rot sets in.
- Screw the corners from the outside in, using two screws per corner, and drill a pilot hole first to keep the wood from splitting.
- Set the frame on level ground, not on concrete or gravel, so water drains away and the wood does not trap moisture underneath.
- You can line the bottom with landscape fabric to slow weeds, but it is not required and will eventually decompose.
Choose your lumber based on how long you want the bed to last
The wood you choose determines whether your bed lasts three years or twenty. Cedar and redwood naturally resist rot and insects, cost $2 to $4 per linear foot, and last 10 to 15 years. Pressure-treated pine is chemically treated to resist decay, costs $1 to $2 per linear foot, and lasts 15 to 20 years. Untreated pine is the cheapest at $0.50 to $1 per linear foot but rots in 3 to 5 years, especially in wet climates.
For a 4-by-8-foot bed 12 inches tall, you need two 8-foot boards and two 4-foot boards. Buy them 2 inches by 12 inches in cross-section (called 2x12 lumber). If you want a taller bed, use 2x16 boards instead, which are 16 inches tall. Do not use treated plywood or composite boards for the sides — they warp and sag under soil weight.
If budget is tight, untreated pine works fine for one or two seasons. If you plan to keep the bed for more than five years, cedar or pressure-treated pine is worth the extra cost.
Gather tools and fasteners before you start
You need a drill-driver (a cordless drill with a screwdriver bit), a circular saw or handsaw to cut lumber to length, a level, a tape measure, and a pencil. If you do not own a drill, you can rent one from a hardware store for $15 to $25 per day, or borrow one from a neighbor. A handsaw works if you do not have a power saw, but cutting four boards by hand takes longer.
Buy exterior-grade wood screws in 3-inch length (also called 3-inch deck screws). You need 16 screws for a four-corner frame — two per corner, two on each side for reinforcement. Do not use nails; they loosen as the wood shifts and the bed falls apart. Do not use interior drywall screws; they snap under soil pressure.
If you want to line the bottom, buy landscape fabric (also called weed cloth) in a roll. A 4-by-8-foot bed needs about 35 square feet, which costs $10 to $20. This step is optional and slows weeds but is not required.
Cut lumber and assemble the frame
Measure and mark your boards. For a 4-by-8-foot bed, your two long sides are 8 feet and your two short sides are 4 feet. If you are using a circular saw, clamp the board to a work surface, mark the cut line with a pencil, and saw slowly along the line. A handsaw takes longer but produces the same result. If the lumber yard offers free cuts, have them cut the boards to length before you leave — this saves two hours of work.
Lay the four boards on the ground in a rectangle. Drill a pilot hole (a small hole that guides the screw) at each corner on the inside face of the board. Use a drill bit slightly smaller than your screw diameter — usually 1/8 inch for 3-inch screws. Drilling a pilot hole prevents the wood from splitting when you drive the screw in.
Drive two screws through each corner, from the outside board into the end of the inside board. Tighten them by hand first, then use the drill to finish. Do not over-tighten; stop when the screw head is flush with the wood surface. If a screw breaks or strips, back it out and drill a new pilot hole an inch away.
Set the frame in place and check for level
Choose a spot that gets at least six hours of direct sun per day and is close to a water source. Clear away grass and weeds down to bare soil. Do not lay the frame on concrete, gravel, or mulch — set it directly on soil so water drains away and air circulates underneath. If the ground is very uneven, dig out the high spots and fill the low spots until the frame sits flat.
Place the assembled frame in position. Use a level to check that the frame is flat side to side and front to back. If one corner is high, dig out soil underneath. If one corner is low, add soil underneath. The frame does not need to be perfect, but standing water inside the bed will rot the wood faster, so aim for level within an inch.
Once the frame is level, you can line the bottom with landscape fabric if you want. Lay the fabric inside the frame, overlap the edges by 6 inches, and staple it to the inside of the boards. Trim the excess with a utility knife. The fabric will eventually decompose, but it slows weeds for the first two to three years.
Fill the bed and prepare for planting
A 4-by-8-foot bed 12 inches tall holds about 32 cubic feet of soil. Buy garden soil or raised bed mix in bags or by the cubic yard. Bagged soil costs $3 to $8 per bag (usually 2 cubic feet); a cubic yard delivered costs $30 to $60 and fills the bed completely. Do not use topsoil alone — it compacts and drains poorly. Use a blend of topsoil, compost, and peat moss or coconut coir.
Shovel soil into the frame until it reaches the top. Water it lightly and let it settle for a day. The soil will compact slightly, so you may need to add another inch or two. Once the soil is settled, you can plant when ready. Do not wait for the soil to "cure" — garden soil is ready to use right away.
Maintain the bed so it lasts longer
Check the frame twice a year for signs of rot or loose screws. If a screw has backed out, tighten it. If a board is soft or crumbling, that section of wood is rotting and will need to be replaced. Cedar and redwood rot slowly; untreated pine rots faster, especially on the bottom edge where it touches soil.
Keep the soil moist but not waterlogged. Wet soil speeds rot, especially in winter. If water pools inside the bed after rain, the ground underneath is not draining well — dig a shallow trench around the outside to redirect water away. In cold climates, the frame may heave slightly in winter as the ground freezes and thaws; this is normal and does not damage the bed.
If you need to replace a board after several years, unscrew the fasteners, slide the old board out, and slide a new one in. You do not need to disassemble the whole frame.
Frequently Asked Questions
Do I need to put anything under the bed to stop gophers or moles?
If gophers or moles are a problem in your area, line the bottom with 1/2-inch hardware cloth (a metal mesh) before you add soil. Staple it to the inside of the frame. This stops burrowing animals but adds $20 to $40 to the cost and makes it harder to replace the bottom board later.
Can I build a bed taller than 12 inches?
Yes. Use 2x16 boards for a 16-inch bed or stack two layers of 2x12 boards for a 24-inch bed. Taller beds need three screws per corner instead of two because the soil weight is greater. They also cost more and take longer to fill, but they are easier on your back when you are planting and weeding.
What if the ground is too hard to dig level?
You do not have to dig. Set the frame on top of the existing ground and add extra soil to compensate. If one corner is 2 inches lower than the others, add 2 inches of extra soil on that side. The frame will settle slightly over the first month, so check it again after a week and add more soil if needed.
How often do I need to replace the wood?
Cedar and redwood last 10 to 15 years. Pressure-treated pine lasts 15 to 20 years. Untreated pine lasts 3 to 5 years. The bottom boards rot first because they touch wet soil. You can replace one board at a time without rebuilding the whole frame — just unscrew the fasteners and slide in a new board.
Can I use composite or plastic boards instead of wood?
Composite boards (made from wood fiber and plastic) last longer than wood and do not rot, but they cost two to three times as much and sag under soil weight unless you use metal reinforcement. Plastic boards are lighter but also sag and can leach chemicals into soil over time. Wood is the most affordable and reliable choice for most gardeners.