10/05/2023
A wicking bed is a garden bed that utilises a reservoir system to supply water to plants from below. To set up a wicking bed, start by selecting a suitable location and constructing the bed using materials such as timber, corrugated iron, or bricks. The bed should be raised off the ground to ensure proper drainage.
Next, add a layer of coarse sand to the bottom of the bed to aid in drainage. On top of this layer, create a waterproof reservoir using a liner such as pond liner or heavy-duty plastic. At the end of the bed that faces downhill, add a hole through the bed and liner, and silicone in a plastic tank outlet. On the inside, add about 1m of small black agri pipe over the outlet to aid in drainage. On the outside of the outlet, add an elbow with a riser cut to a height so that the water level is about 20mm below the top of the screening. This prevents the soil from being too wet, and the water will easily climb through the stone to dampen the soil. The moisture level can be adjusted by cutting or tilting the riser on the outside.
It's important to note that the water reservoir in a wicking bed should be filled with a layer of small screenings or scoria to aid in water distribution to the soil above. Cover this layer with a geo fabric at a depth of 200mm to 300mm. The geo fabric will prevent the soil above from mixing with the water reservoir and also help distribute water evenly throughout the bed. This setup creates a self-watering system for plants, ensuring a steady supply of water while minimising water usage.
Above this reservoir and geo fabric, fill with a suitable growing medium, such as a mix of soil and compost. Insert a PVC pipe or similar vertically into the centre of the bed, reaching down to the reservoir, to allow for water to be added without disturbing the soil.
Finally, add a layer of mulch or organic material on top of the soil to help retain moisture and prevent w**d growth. Once set up, the wicking bed will provide a consistent supply of water to plants, reducing the need for regular watering and ensuring healthier and more productive plants.