A planter is an enclosed box filled with dirt and plants. This form of container gardening provides people who lack garden space or have poor-quality soil a chance to grow beautiful flowers and enjoy their sight and smell. It can be built to a certain height by placing "legs" under each corner, preventing people with back problems from bending too low when tending to their plants. Planter boxes are very portable, and can be placed indoors or outdoors to provide a splash of color against any backdrop.
Decide the height, length and depth of the planter. Measure a spot where you want to place the planter so it fits perfectly. Ideally, a height of 8 to 12 inches provides sufficient space for most roots to grow and spread. It can be as long as you like, but opt for two medium-length planters in place of a very long one so moving it at some point in the future will be easy. Also keep it up to 3 feet wide so you can easily reach the center from all sides.
Mark the appropriate lengths on the board with your measurements, and cut over the lines with a handsaw so you have five lengths for the planter. Cut two identical boards for the front and back, two identical boards for the sides. Also cut a lower piece as wide as the side but as long as the front and back.
Drill rows of ½-inch wide drainage holes in the lower base piece. Provide a spacing of 4 inches between rows, with holes spaced 6 inches apart.
Lay the base piece over a flat and even surface. Place the front piece flush against its long edge, ensuring its lower long edge rests on top of the even surface. Drill a row of wood screws into the lower edge, spaced 8 inches apart, which will penetrate the base to join both pieces together.
Hold one of the short sides in place, ensuring the joints between the base and front are flush and even. Drill wood screws into its lower edge to join it to the base. Also drill wood screws through the front piece that will penetrate through the side to join them both together. Repeat the procedure with the second side to join it to the front and base.
Place the back board in place between the short sides, until it is flush against the base. Drill it into place at the base and both the sides. Review your planter box to make sure it is sturdy, and reinforce any joint by drilling another screw.
Sand the planter box to remove sharp edges. Paint it a bright color so it stands out.