A planter box is the perfect way to spruce up your outside area. Plant flowers, herbs or plants in them that will add color to a particular spot, make it stand out against any background and enhance interest and appeal. These are portable, allowing a home owner to place them anywhere he or she wants, and increase productivity because every inch of soil is specifically meant for planting. Fill your rectangular planter box with a blend of towering and cascading plants or flowers so relaxing there is even more pleasurable.
Decide where you want to place the planter box. If you have any specific spot in mind, measure it so you can decide its length, depth and width appropriately. For a general box you will place somewhere once it's made, keep it 10 to 12 inches deep and up to 3 feet wide. Making it any wider will prevent you from accessing the plants growing in the center.
Select good quality wood from a hardware store. You can use softwoods or hardwoods, depending on your budget and individual preference. Keep in mind, however, that softwoods, albeit cheaper and easier to work with, tend to sag with time, while hardwoods maintain their shape for many years.
Cut your boards to size using a handsaw. Cut two identical long boards for the front and back of the planter box, two small boards for the sides, and a board that is equal in length to the front and back, but as wide as the sides. This last piece will be the base of the planter box. For a square planter, cut five identical boards.
Select a flat and even surface, such as a worktable to work on. Place your five wooden boards and the necessary hardware over the top.
Hold the front piece and place one of the sides flush against it. Align the two pieces so their tops are at the same level, and join them together by drilling 1-inch woodscrews into them. Check the structure to make sure it is secure and repeat the process with the other short side.
Place the back piece between both the side pieces and align it so its top is at the same level. Join it to the structure by drilling woodscrews into both the sides that will penetrate the back. Turn the planter box so its base-cavity faces up.
Drill 1-inch drainage holes in the base piece, spaced 6-inches apart. Carefully lower it over the base-cavity so its rests securely on all four edges. Drill woodscrews into each edge so it is secure.
Turn the planter box over and stand it on your worktable. Check the stability of all the joints, and drill an additional wood screw into any joint that needs reinforcement. Sand any rough edges or splinters, and apply a coat or two of clear or colored paint so it can withstand natural elements outside.
Allow it to dry overnight before filling it with dirt.