When installing planter boxes on wooden decks, proper drainage is crucial to protect your deck structure and maintain plant health. The key is creating a system that allows excess water to escape without damaging the wood surface beneath.
Start by selecting planter boxes with built-in drainage holes. If your boxes lack these, drill several 1/2-inch holes spaced evenly across the bottom. For additional protection, elevate your planters slightly using pot feet or wooden slats to create air circulation beneath.
Create a layered drainage system inside each planter. Begin with a landscape fabric liner at the bottom to prevent soil from washing out while allowing water to drain. Add a 2-3 inch layer of coarse gravel or lava rocks above the fabric. This layer acts as a reservoir for excess water while keeping soil from becoming waterlogged.
Consider using plastic liners with pre-drilled holes as an extra protective barrier. These liners prevent constant moisture contact with the wooden planter walls, extending their lifespan. For particularly sensitive deck surfaces, incorporate a drip tray beneath each planter, but remember to empty it regularly to prevent standing water.
The soil mixture itself contributes to drainage. Blend quality potting soil with perlite or coarse sand to improve drainage capacity. A good ratio is three parts potting soil to one part drainage material.
Regular maintenance completes your drainage solution. Check drainage holes monthly for clogs and clear any debris. During heavy rain periods, consider temporarily moving planters or adding extra drainage materials. With these thoughtful drainage approaches, your urban garden can thrive while your wooden deck remains protected from water damage.