Raised beds provide a planting alternative to gardeners where soil conditions are poor or adequate space is a problem. They resemble boxes without any tops or bottoms and are used to demarcate and define flowerbeds while enhancing the appearance of the landscape. They can also improve drainage within the confines to promote optimal growing conditions. Raised beds are also made on concrete or tiled surfaces when garden space is not available.
Select a spot in your garden, yard or drive where you want to install the raised beds. You can draw a sketch on paper to design where you want to place the beds. This will also give you an idea of how many you need to make. Also decide how high you want to make the beds, keeping in mind any surrounding beds and the landscape. Ideally, a height of 12 to 15 inches is suitable with a thickness of 2 to 3 inches. Leave enough space between beds for a path, and avoid making them so wide that reaching the plant or flower growth in the middle becomes a problem.
Decide on the material to use for the raised beds. You can use railroad ties or timber for small beds, or pressure-treated lumber for large-sized beds. Make square or rectangle beds depending on the space available.
Purchase boards of cut wood from your local hardware store in the appropriate size, or cut it yourself with a circular saw. Fir is more economical than cedar and redwoods. You will need four lengths of wood per single bed; all will be the same length for square beds, or two long and two short for rectangular-shaped raised beds.
Mark your beds with powdered chalk or spray paint. Remove 2 to 3 inches of soil from the demarcated area to make a shallow trench that will support the raised beds; collect the soil in a wheelbarrow.
Take one length of board and place it on the ground. Place the corner of another board flush against the first board's corners, and drill a hole to screw them into each other. You will now have an L-shaped frame. Repeat the procedure with two other boards, and connect the two L shapes to each other to form a box that is a square or rectangle. If your boards are high, drill two holes, one at the top and the other at the bottom of each corner, to make them secure.
Place the box into the trench and spread a layer of gravel in the base to improve drainage.
Fill the box with garden soil, or good quality potting soil if your garden soil is poor. Also add some compost to the bed and rake it in so it mixes with the soil to improve its quality.