We’ve created a sequence with all the info you need to get started building your own wicking bed – i.e., a veggie bed that waters itself from below. It’s based on our years of experience installing wicking beds in Melbourne, Australia. We sincerely hope your water wicks well and your garden grows green and lustrous. Let’s start with the basics—and wonders—of wicking beds:
When we first started Very Edible Gardens (VEG) back in early 2009, we had no idea what a wicking bed was. Then, after a year or so of installing raised vegetable garden beds all over Melbourne, someone whispered the words into our ears. “Wicking beds,” they said. “We want some wicking beds.”
“Wicking beds” we thought, smiling and nodding, then scratching our heads. “What on earth is a wicking bed?” So we did some research and, equal parts intrigued and skeptical, we started to experiment. Up till then, all our raised veggie beds had been either hand-watered or set up with ‘dripline’ irrigation. But now we started setting up wicking beds in old bathtubs:
…and then, using plastic liner, in our raised VEG beds which are assembled from sleepers of locally harvested golden cypress (Cupressus macrocarpa) timber:
Invented by an Australian named Colin Austin, the idea with a wicking bed is that you prevent water from leaving the bottom of the bed with a waterproof liner or layer. This creates a water reservoir underneath the soil. Then, rather than having to irrigate by watering from above (via drip irrigation, a hose, watering can etc), the water literally wicks up into the soil from below, keeping it nice and moist.
Now, with all that water, this could easily get messy and even stinky. But, you prevent the weight of the soil from squashing all the water out – and making a muddy mess – by having the water sit within a layer of small stones, which is able to accommodate the water whilst bearing the weight of the soil (and your prize pumpkins!) without collapsing. You prevent the soil from washing down into gaps between the stones with a sheet of something that lets water wick up, but stops soil moving down.
Then you have your happy soil and plants on top of this.
The last essential piece of the wicking bed puzzle is that you need an overflow point (usually a pipe) so that the soil layer doesn’t get flooded, which would kill the soil life and plants by rotting their roots. (With the VEG Wicking Bed style ones you install them before you add the soil or stones.)
As you’ll know if you’ve researched wicking beds online, the available information is scattered about the web in dribs and drabs and often with advice that contradicts what the other site said. So, taking it all with a grain of salt, we set out to learn by doing, our initial intention to prove to ourselves that wicking beds didn’t work. We gave it a pretty good shot, and in the process we learned a lot, and refined how we go about them enormously.
We’ve condensed all this knowledge into our How to Make a Wicking Bed sequence. But before you rush out and build one, take a moment to consider the pros and cons…
Let us level with you here. Yeah, we sell these things. And we love them. But, we’re not interested in selling them to anyone where it’s not the right solution. So this is our truest, honestest, bestest list of the formidable pros, and some realistic cons of wicking beds. So read on, to help decide whether or not wicking beds are the right choice for you.
Ok, so you do want to consider your options, but here’s what one client, Rosalie, said about her beds:
The original two wicking beds were so successful that I had the other three converted. One of the original two was planted with silver beet when I went away in Sept 2014 and another non wicking bed also planted. I was away for four weeks. When I came back the difference between the two beds was amazing. One was lush, the other just OK. This was what convinced me to convert the other three.
As for water usage, they are a miracle. I have only a 3000L tank and it would regularly run out in the first month of summer. Since the wicking bed installs I have had two summers and the tank hasn’t run out for either. I know this has a lot of other variables like temperatures and rainfall, but anecdotally they save water. I fill them once a week, or twice if we have baking heat in the high 30s+. It takes far less time to fill them than if I had the dripper system running – i.e., minutes as opposed to hours.
The reason we recommend and install so many wicking beds is that they work. In Melbourne’s hot dry summers the veggies continue to thrive with a fraction of the water otherwise required. On the two occasions we have installed or converted one or two of a larger number of raised beds as wicking, the customers have both in short order got us back to convert the rest. The difference in plant health and growth is just so stunning.
Righteo then! If you’d like a hand getting your wick on in your backyard, then there are three main ways we can help: