Proper drainage is crucial for healthy plants in urban planter boxes. Start by ensuring your containers have adequate drainage holes—at least one half-inch hole per square foot of soil area. If your planter lacks holes, drill several in the bottom before adding soil.
Create a drainage layer by adding two inches of coarse material like gravel, pebbles, or broken pottery shards at the bottom of your planter. This space allows excess water to collect away from plant roots. For additional protection, place a permeable landscape fabric between the drainage layer and soil to prevent soil from washing down while allowing water to pass through.
Choose a well-draining potting mix specifically formulated for containers, as regular garden soil becomes too compact. Consider adding perlite or coarse sand to improve aeration. When watering, check soil moisture by inserting your finger two inches deep—water only when it feels dry.
Elevate your planters slightly using pot feet or bricks to create air space underneath, promoting better drainage and preventing containers from sitting in standing water. Monitor your plants for signs of poor drainage including yellowing leaves, wilting despite moist soil, or fungus gnats. With these simple steps, your urban garden will thrive with optimal moisture levels.