When designing an urban garden, one common question arises: should planter boxes be elevated off the ground? The answer is generally yes, and for good reason. Elevating your planters provides crucial benefits that can make the difference between thriving plants and disappointing results.
The most important advantage is improved drainage. When planter boxes sit directly on hard surfaces like concrete or decking, water can become trapped at the bottom. This waterlogging creates anaerobic conditions that suffocate roots and promotes root rot. By raising planters just a few inches, you allow excess water to escape freely, maintaining the healthy oxygen levels roots need.
Elevation also provides protection against pests. Ground-dwelling insects like slugs and snails have difficulty reaching elevated plants, reducing the need for chemical pesticides. Similarly, raising planters creates a physical barrier against soil-borne diseases and prevents wooden boxes from constant moisture contact that leads to rot.
Beyond plant health, elevation offers practical benefits for the gardener. Raised planters reduce back strain by bringing the gardening surface closer to you—no more bending over to tend to plants. This accessibility makes urban gardening more enjoyable and sustainable long-term. The air circulation beneath elevated boxes also helps prevent moisture damage to your patio or balcony surface.
How much elevation is needed? Even 2-4 inches can significantly improve drainage. For larger planters, consider 6 inches or more. You can achieve elevation using purpose-made planter feet, bricks, wooden blocks, or purchasing planters with built-in legs. Just ensure whatever method you choose provides stable support and doesn't block drainage holes.
While not absolutely mandatory for all situations, elevating urban planter boxes is a simple practice that delivers substantial rewards. Your plants will thank you with stronger growth, better health, and more abundant harvests or blooms.