How to Build a Box for a Large Outdoor Planter

Stand your two 2-by-3-foot plywood pieces on their 3-foot-long sides and space them 2 feet apart. Place a 2-by-2-foot piece of plywood between the larger boards at each end to form a rectangular box shape. Screw through the 2-by-3-foot pieces and into the 2-by-2 pieces at each corner, spacing the screws 6 inches apart.

Stand a 2-by-6-inch board on its 2-inch width and place it inside the box up against one of the 2-by-2-foot pieces. Set a second 2-by-6-inch board against the other 2-by-2-foot piece. Screw through the 2-by-2-foot pieces and into the 2-by-6-inch pieces every 6 inches to secure.

Place your remaining 2-by-6-inch pieces also on their 2-inch width inside the box and space them evenly apart by approximately 1 foot. Screw through the 2-by-3-foot boards and into the ends of the 2-by-6-inch boards to secure.

Lower your 24-by-35-inch piece of plywood into the box and press it down until it comes into contact with the 2-by-6-inch supports. Screw through this bottom piece and into the supports every 6 inches to secure. Drill six 1/2-inch holes through the plywood bottom spacing the holes evenly apart to create adequate drainage.

Line the inside of the box with black landscaping plastic, using a staple gun to secure the plastic every 8 inches. If multiple pieces are needed, try to overlap the pieces by 4 to 6 inches. Use a screwdriver or other pointed item to poke a hole through the plastic where it corresponds to the six drilled holes in the bottom of the box.

Place the box where you want it before filling with a base of 1 to 2 inches deep of gravel followed by potting soil and your desired plants.