Wooden planter boxes add natural beauty to urban gardens, but they're vulnerable to rot from moisture and soil contact. The best protection starts with selecting naturally rot-resistant woods like cedar, redwood, or pressure-treated lumber. These woods contain natural oils or preservatives that resist moisture damage and decay.
Ensure proper drainage by drilling multiple holes in the bottom of your planter box and adding a 1-2 inch layer of gravel or stones before adding soil. This prevents water from pooling at the bottom, which is a primary cause of rot. Consider lining the interior with landscape fabric or plastic sheeting with drainage holes to create a barrier between the wood and moist soil.
Applying a wood sealant or preservative is crucial for longevity. Use a non-toxic, water-resistant sealant specifically designed for garden use, applying it to all surfaces, especially the interior. Reapply annually or as recommended by the manufacturer. Elevating your planter box slightly off the ground using bricks or feet improves air circulation and prevents ground moisture absorption.
For additional protection, consider using a plastic insert or container inside the wooden box, ensuring it has adequate drainage. Regular maintenance including cleaning debris from between boards and promptly replacing any rotting sections will significantly extend your planter's life. With these protective measures, your wooden planter boxes can remain beautiful and functional for many growing seasons.