Past Articles Library | Building a Three Board Raised Bed
Raised beds have a number of advantages: better drainage, better soil, easier access, and ease of irrigation. Often, however, it seems you must have a degree in engineering to build one. This article will explain how to build a raised bed using just three boards and some nails or screws.
First, the materials. You will need to buy three 1X12 inch boards that are eight feet long. One of the boards will be cut in two, so if you do not have a saw, ask your lumber supplier to make the cut. Most places will make one cut free, or for a nominal fee. You also need a box of number 8 woodscrews or 6d nails that are around 2 inches in length.
After the cut, you end up with two eight foot boards and two four foot boards. Lay them out in a rectangle where you are going to place your raised bed. The finished bed is unwieldy, so you do not want to have to move it once you build it.
Next, start nailing the boards together. You will be using butt joints, which just means you overlap the boards and nail them together. The first corner is the hardest unless you have help, but you can build this without a helper. I know, because I built it without any help.
After you nail all the corners together, you are done. You now have a four foot by eight foot bed that is one foot high. In order to use it, you need to fill it with dirt. Most communities have a vendor that sells topsoil. You can have it delivered or, to save money, you can go get it yourself.
Before you fill your bed with dirt, there are a few frills you might want to add. If you live in an area with a lot of moles and gophers, you can tack chickenwire over the bottom of your frame to keep them from being able to dig in. This will help keep your plants safe.
Second, if you have some pieces of wood that are the right size for stakes, you can put a couple in the ground about the center of each eight foot board. This not only holds the bed in place, it helps keep the board from bowing out when the soil is placed in the bed.
Finally, to prevent weeds from growing in your nice raised bed, spread newspapers on the bottom of the bed before adding soil. Newspaper will block the germinating weed seeds from coming up in your garden. The newspaper lets water through and will eventually decompose. However, the weeds have usually given up before that happens. Most newspapers now print with soy ink so it is not toxic.
This raised bed design allows you to reach everywhere in the bed without walking in it. You will not have to step in the bed and compact the soil. Further, if you have someone who cannot stand long, you can simply add more boards to the design and stop at a comfortable height for them to sit and do their gardening. If you do that, you will have to nail one inch by two inch strips to the frame to join the two or three boards so the soil will not push them apart.
Square foot gardening is an intensive cultivation method that is ideal for beds such as this. To use it, you first put a nail in the top of the board frame every foot, all the way around. You then tie string from one nail to the nail across from it, forming a grid of one foot square spaces. You can grow the following in each grid:
One large plant such as a tomato or pepper
Four plants such as leaf lettuce
Nine plants such as bush beans
Sixteen small plants such as carrots
If you harvest your crop when it is ripe and then plant another group of plants in each square, you can grow a lot of food this way. Because the plants are densely planted, weeds are crowded out in most cases.
Good luck with your raised bed. You can find more information on square foot gardening at the Square Foot Gardening Foundation webpage.