Growing plants in a planter offers the ability to garden even if the soil isn't usable and makes plants accessible to gardeners who have difficulty working at ground level. By building a hexagon planter, rather than a square or rectangle, you add visual interest to the plants' container and enhance the look of your garden area. Once you have finished building the planter, you can set it directly on the ground and plant into it as desired.
Measure the ends of a board along the 5-cm (2-inch) width with a protractor and use a pencil to mark a 30-degree angle. Make sure the length of the board remains 90 cm (3 feet) on one side and the angle cuts into the other side on both ends of the board. Repeat for each of the six boards.
Stand two boards on their 5-cm (2-inch) widths. Align the angled ends together so the cut surfaces meet and both 90 cm (3 foot) long sides are facing out. Secure the two ends using three evenly spaced screws. Repeat to make two more angled units like this.
Pair two of the connected units to one another along one end and secure with three screws. Add the final connected unit to the four connected boards, aligning the ends and secure with screws to complete the hexagon shape.
Hold a 5 by 5 cm (2 by 2 inch) stake to the inside surface of one of the six corners. The stake will be taller than the 40-cm (16-inch) walls of the planter. Screw two evenly spaced screws through the stake and into the planter to secure. Repeat with the other five corners and stakes.
Flip the hexagon planter over and move it to the area where you want to grow your garden, selecting full or partial sun, as desired. Place the planter on the ground and push the stakes through the soil. Use a rubber mallet, if needed, to set the bottom of the planter at ground level.
Layer landscaping fabric over the ground surface along the inside of the planter. Overlap any pieces as necessary by 10 cm (4 inches). Fill the planter with garden soil to within 2.5 cm (1 inch) of the top and plant as desired.
Select cedar wood for this project for its natural rot resistance, or use a moisture-retention sealant on the planter before placing in the ground, if you're concerned about getting the most years possible from your planter.