Making outdoor planters from wood requires treated or special wood that will withstand the elements and be resistant to insects. You can make outdoor planters from cedar or teak boards, or you can build a planter box from marine plywood, and cover it with decorative mosaic pieces or copper sheeting to fit your patio or deck décor. You can also paint your plywood planter with exterior or acrylic paint or stain for a simple and inexpensive solution to accessorizing your outdoor space.
Determine the desired height and width of your outdoor planters based on the available space and on the types of plants you plan to grow. You can make any size square or rectangular planter with marine plywood.
Measure and mark the plywood to fit the dimensions of the four sides and the bottom of your planter. For example, if you're making a rectangular planter that's 12 inches high, 20 inches long and 10 inches deep, you'll need two sections of plywood measuring 12-by-20 inches for the front and back of your planter. You'll also need two sections measuring 12-by-11 inches for the sides of your planter. The sides measure 11 rather than 10 to account for the width of the plywood. The bottom of this planter will measure 20-by-9 inches to fit inside the four sides, less the thickness of the plywood.
Make the planter box by attaching the four sides together with decking screws. Butt the front and back panels against the side panels, and then insert the screws through the side panels into the front and back panels. Place screws every 2 inches. Attach the bottom of the planter by inserting screws through each of the four sides into the bottom piece.
Drill drainage holes into the bottom of the planter. Cut a sheet of plastic to fit inside the planter, and attach it with staples. Puncture the plastic as it falls over the drilled drainage holes.
Cut the copper sheeting so that it fits the outside face of your planter, the top edges of the planter and 4 inches along the inside edge of the planter. Do not cover the bottom of the planter with copper.
Attach the copper to the planter box with waterproof adhesive along the flat face of the sides and copper nails along the inside edge.