Self-watering raised bed (wicking bed design)

Self-watering or wicking beds have a built-in water reservoir beneath the soil, separated by a wicking layer that draws water upward through capillary action. Plants access a consistent moisture supply from below, and the reservoir only needs refilling every 3-7 days. Build a wicking bed by lining the bottom 6-8 inches of a raised bed with pond liner or heavy-duty EPDM rubber, creating a waterproof reservoir. Fill the reservoir zone with coarse gravel or perlite. Lay landscape fabric over the gravel to separate it from soil. Install a fill pipe (PVC, 2-3 inch diameter) from the top of the bed down to the reservoir for refilling. Add an overflow drain at the top of the reservoir layer to prevent waterlogging. Fill the upper portion (10-12 inches minimum) with standard raised bed soil mix. Water is added through the fill pipe and wicks upward to roots. This design reduces water usage by 50%+ and is especially valuable in hot climates, for gardeners who travel, or for community garden plots where daily watering is impractical. Cost: $40-80 in additional materials beyond a standard bed.