Wicking beds are a type of self-watering, raised garden bed with a water reservoir built into the base. Water is drawn or ‘wicked’ upwards through the soil to the plants. Watering this way avoids some of the disease issues associated with watering from the top, encourages deeper root growth, and produces stronger, healthier and more drought resistant plants.
Wicking beds are a great investment for drought proofing your garden and saving water. You can use as much as 80% less water with a wicking bed.
Here’s one common way to convert an existing bed to a wicking bed.
The empty bed is first lined with a waterproof liner, like a pond liner. A loop of agricultural (perforated) pipe is placed on the bottom and the reservoir is filled to about 20–30 cm deep with gravel, scoria, or coarse sand. A layer of landscaping (or geotextile) fabric is laid on top of the gravel to separate the soil from the gravel while allowing water through. Finally the bed is filled with soil to a depth of about 30 cm. The reservoir is filled via a vertical pipe that runs from the top of the bed into the pipe in the base. There is also an overflow pipe at one side to prevent overfilling the reservoir and flooding the bed.
There are a variety of ways to build a wicking bed and many resources online. There are alternatives to making the reservoir with gravel and geotextile, like the modular wicking cells produced by our Trail sponsors, Water-ups from Down-Under.
You can buy ready-made wicking beds, like the small Vegepods, and custom-made kits like those made by Water-ups from Down-Under and Very Edible Garden Wicking beds, or make your own. You can also make beds from plastic tubs and old baths, in which case you won’t need the waterproof liner.
See our other Edible Garden Tips for more water-saving ideas!