Placing planter boxes on a wooden deck adds greenery but requires smart drainage to protect the deck. The best way involves a multi-layer system. First, always use planter boxes with drainage holes. Inside the box, create a drainage layer at the bottom using materials like pebbles, gravel, or broken pottery shards to prevent soil from clogging the holes. Place a permeable landscape fabric over this layer to keep soil in while allowing water to pass through.
Crucially, never let the planter sit directly on the deck. Use "pot feet" or a stand to elevate the box, ensuring air circulation and allowing water to escape freely. For extra protection, place a durable waterproof tray or a deck protector mat underneath to catch any excess runoff. Consider a secondary overflow hole a few inches above the base as a safety measure against overwatering. Regularly check that the drainage holes are clear. This approach effectively manages water, keeps your plants healthy, and preserves the integrity and beauty of your wooden deck for years to come.