What makes wicking beds wick?

Wicking BedsThere’s a lot of talk about wicking beds these days, and for good reason, as they are incredibly efficient with water. There are many other benefits, but first, what exactly is a wicking bed?

Essentially, a wicking bed is a raised bed with a water reservoir in its base that supplies moisture to the growing medium above. The moisture is drawn up into the soil by capillary action, the same force you see when you dip a piece of fabric into water (hence the term ‘wicking’). Think of a wicking bed as a giant self-watering pot.Here are six reasons to consider growing plants using this method:

1. Water from the reservoir is distributed evenly to the root zone.
2. Plants rarely suffer the stress of being too wet or too dry, as they automatically receive the right amount of water.
3. There is no run-off, reducing water waste.
4. Less nutrients are lost through leaching. Even with top-watering, any leached nutrients are contained within the reservoir and re-absorbed into the root zone.
5. The reservoir offers an effective and efficient way to apply liquid fertilisers.
6. Wicking beds have a sealed base, so they can sit on hard surfaces, such as concrete or paving, allowing you to grow vegies and flowers in courtyards and on rooftops that can support the weight. They also offer a solution if the garden’s soil is contaminated or invasive tree roots are a problem.

Wicking beds are available in different shapes and sizes, sometimes marketed as raised garden beds (with a wicking option) or self-watering pots. You can see how to make your own simple self-watering pot at home in the October issue of ABC Gardening Australia magazine, on sale now.