Our planter box factory offers both elevated and ground-level designs, but for heavy clay soil, we strongly recommend elevating the boxes. Clay soil drains poorly and compacts easily, which can suffocate roots and cause waterlogging. By raising the boxes off the ground with legs or a stand, you create a physical barrier between the engineered growing medium inside the box and the dense clay beneath. This allows excess water to drain freely away, while air circulates underneath, preventing root rot and promoting vigorous growth. Even without legs, you can place our boxes on a gravel base, but the factory-elevated models include a built-in drainage gap and a breathable bottom liner. If you choose to set the box directly on dirt, we would advise amending the clay with coarse sand and compost first—but honestly, for long-term success and low maintenance, elevation is the smarter, more productive solution. Our raised planter boxes are crafted from rot-resistant cedar or recycled composite, and the under-frame is engineered to support heavy wet soil without sagging. Visit our factory or browse online to see models with adjustable leg heights. Your plants will thank you.