If you're handy and want to add greenery to your urban space, building your own planter boxes is a rewarding weekend project. Start by gathering materials: cedar or redwood boards (naturally rot-resistant), exterior-grade screws, landscape fabric, a saw, drill, and measuring tape.
First, determine your box size - 24x24 inches is versatile for most balconies. Cut your boards: two equal lengths for front/back, two shorter for sides, and additional pieces for the base. Pre-drill holes to prevent wood splitting, then assemble using 2.5-inch exterior screws. Create a frame by attaching sides to your longer boards, forming a rectangle.
Line the interior with landscape fabric, stapling it securely. This allows drainage while containing soil. Drill several 1/2-inch drainage holes in the bottom, spacing them 6 inches apart. For elevated planters, add corner legs cut from 2x2 lumber.
Finish with a weather-resistant stain or sealant. Fill with quality potting mix, leaving 2 inches from the top. Your custom planter is ready for herbs, flowers, or small vegetables. Remember to consider weight - large planters can be heavy when filled, so position them thoughtfully. Regular maintenance includes seasonal cleaning and checking for wood wear.