A wicking bed is a garden bed with a waterproof lining that holds a reservoir of water at the bottom from which water is draw upwards like a wick to the surface of the bed via natural soil osmosis or through the roots of plants in the bed.  Basically it works like large Decor self-watering pot. 


Wicking beds are usually made with timber sides and a pond liner at the bottom to act as a water reservoir, but they can also be made  out of plastic tubs or any other container that holds water and does not corrode when in contact with soil. 

There are many different wicking bed designs involving a variety of construction materials however this website only looks at ones that I have made and tested myself.