A wicking bed is an excellent technique for growing things in environments where water is scarce. It’s got two main parts: the bottom half is a contained reservoir filled with gravel and water and the top half is filled with soil, mulch and plants. By periodic flooding of the deeper half of the bed, mature plant roots get a big drink. And because it’s contained, that water gets a chance to ‘wick’ upwards into the soil, hydrating the soil of the bed and the smaller roots within.
Pretty simple, really, but amazingly effective, very water efficient and ripe for endless variation.
The first step is to create the reservoir which will hold the gravel and the water. This bed shape and size is based on the footprint of a watertank, a strip of which we’d found to use for the sides of the bed. Make the reservoir around 30cm deep, regardless of the size or shape of your bed.