What is Wicking Beds?
According to the Colin Austin, inventor of Wicking Beds:
The basic wicking bed system works in its most basic consist of a barrier to the water escaping deep into the soil, this can be made by digging a hole and lining with a plastic sheet or a bucket. Another version is to have a conventional planter pot but instead of having drainage holes in the base it has the drain hole in the side so water accumulated in the base of the planter pot.
It works by preventing the water draining away from the soil, so it becomes saturate rather than at field capacity. The amount of water in the soil at saturation, when all the large holes are filled with water is much higher than field capacity, it could be as much as double the field capacity is a well aerated soil, and as the available water is the amount of water above the wilt point the increase in water holding capacity is significant – multiples of a conventional free draining soil.
Despite being so simple they are very effective, more sophisticated versions can be made with pipe work to distribute the water or an inverted container (with bleed hole) to store the water.
Here is a great illustration of Wicking Beds and how it works:
My Backyard Wicking Beds
The finished beds
How they were built
Digging a hole on the ground about 20 cm deep.
HDPE pond liner as base.
Mulch with grass clipping
Brewing worm compost tea to be applied
It should take about a week or so for the microbes community to build up and the beds will be ready to grow some vegetables!