Remove all plant matter and debris from the area you wish to place the wooden planter. Dig up all remaining vegetation, rocks and rubble from the space.
Cut and place the base of the flowerbed along the outer edges. Place a bubble level on top of each piece to ensure the frame is level and use a power drill to screw the corners together.
Drive long edge posts along the corners of the wooden flowerbox into the soil and drill screws into the sides.
Saw off the tops of the posts if they stick out over the top of the flower bed's frame. Pack the flower bed with soil and save the best soil for the top layers where you will plant the flowers.