If you have ever torn down an old wooden fence or deck you know exactly how much wood you have to get rid of. And some of that wood will still be in fairly good shape. There is a lot you can do with it besides throwing it away. One easy thing to do, not to mention something that will come in handy as well as add some character to your landscaping, is making rustic looking flower boxes from all that old wood. It is a great way to reuse something old that still has a purpose.
Measure out the desired size of your flower box from the plywood. This will act as the base of the flower box. Cut out the base using a circular saw.
Look carefully through the old fence or deck wood and find pieces that are not split or rotting. Use these pieces to build the walls of your flower box. If there are any old screws or nails in the wood, remove them and throw them away.
Place your mitre saw on a worktable. Measure out the lengths that you need from the old wood. Cut those lengths with the mitre saw. For example, if you are making a 100 by 40 cm (40 by 16 inch) flower box, then you will cut the length boards to 100 cm (40 inches) and the width boards to 40 cm (16 inches). How many of each that you cut will depend on the depth that you are making your flower box and the size of the wood that you are using.
After you have cut all the pieces of wood for the walls of the flower box, stack up each wall individually and then lay it down flat on the worktable. Cut another old piece of wood from the fence or deck for the support beam. Lay it perpendicular in the centre of the stacked wall. Using 3.75 cm (1-1/2 inch) screws (or whatever size you need to attach the support beam properly --- this will vary, depending on the thickness of your wood) attach each piece of wood to the support beam. When you are finished, all the pieces of the wall should stand as one piece (see above picture). Repeat this same process with the other three walls. When you are finished you will have four walls, not yet attached to each other.
Attach one side wall to an end wall using 7.5 cm (3-inch) screws (you will go in through the end walls). Attach the second side wall and then the last end wall in the same way. When you are through with this step you will have a box without a bottom.
Turn the wooden box upside down and place your precut base (from the plywood) on top. Attach the bottom to the box with 7.5 cm (3-inch) wood screws in all four corners and in the centres.
Flip the flower box back over. Drill two holes in the bottom of the base for irrigation using a 2.5 cm (1-inch) spade bit. Fill to within one inch of the top with potting soil, plant your favourite herbs or flowers and enjoy your new flower box!