Garden Raised Beds
For gardeners faced with poor, shallow soil, raised beds are the perfect solution. Raised beds can be as easy as mounding rich topsoil to create a suitable planting area.
If your soil is impenetrable below a few inches, you'll need to construct a box to place on top of the garden bed. To construct a raised bed, select a level, sunny site, and dig as deeply as you can to loosen the soil. You can form the above-ground walls with almost any solid material, such as stone, brick, or rot-resistant lumber such as red cedar.
For vegetable and herb gardens, avoid using pressure-treated lumber, which can leach heavy metals into the soil. The walls can extend above the ground from a few inches to a foot or more. Then fill the box with topsoil, compost, well-rotted manure, and other organic matter. The beds shown here, made of 2-by-12-inch rot-resistant lumber, have interior dimensions of 3 feet by 20 feet.
- Surveyor's string
- Corner stakes
- Edging tool
- Pick, shovel, and garden fork
- 2 precut 10-foot boards and a two to three foot third board
- Wood chip mulch
- Landscape fabric
Mark the bed layout with surveyor's string and corner stakes. When calculating the perimeter, allow for twice the thickness of the wall material so the inside area doesn't get skimpy. (For instance, add 3 1/2 inches to the dimension to allow for the 2-inch lumber, which is actually 1 3/4 inches thick.)
Make corner stakes from 1-by-2s cut on an angle.
Cut the turf with an edging tool along each bed's perimeter.
Using a pick, shovel, and garden fork, loosen and remove clods of turf to the compost heap.
Once the turf clods are removed, loosen the underlying soil as deeply as possible, preferably 12 to 18 inches. In compacted or rocky areas, a pick or large pry bar may work better than a shovel or fork.
Build the long walls of the beds first, using 2 precut 10-foot boards, butted together and secured with a short third board, nailed to the inside surface.
Dull the nail heads with a hammer to prevent the wood from splitting when nailing the boards to the box.
Cut the third board about 2 or 3 feet long and 1 to 2 inches narrower than the bed wall so it can be fastened to the bottom of the interior bed wall and will not show at the soil surface.
Assemble the beds by nailing together the corners in a simple butt joint. Because beds longer than 10 feet can wobble, position crossbraces made of 2-by-8s inside the bed and nail them from outside. Position the top edge of the brace below the top edge of the bed to hide the brace.
Cover the paths between the beds with landscape fabric, a synthetic material that allows water to drain but prevents weeds. Tuck the fabric beneath the beds, lifting them with a pry bar. (Add wood-chip mulch later.)
Once the beds are in place, slightly below soil grade for stability, secure them with interior corner posts (made of rot-resistant 2-by-2s cut on an angle at one end and long enough to be driven into the soil below the frost line). Knock the posts into place with a sledgehammer until they're 1 to 2 inches below top of wall; then nail them to the box. Fill the finished bed with topsoil mixed with compost and other organic matter, and mulch the paths.