The concept of wicking is something that every good gardener should know about. Essentially, it is the process where an object soaks up moisture. It’s like when you put a piece of string in a glass of water, and the water climbs (or wicks) its way up the string.
The roots of plants use the same concept to draw water from the soil.
A wicking bed takes advantage of this process by creating a layer of water underneath the soil from which your plants draw water and nourishment.
You will find many examples of wicking pots in most garden stores, and these are basically known as self-watering pots. However, a wicking garden bed goes much further to create a long-lasting solution to problems that many gardens face.