Make your bed and eat off it too. Jimmy Cocking
A queen-‐sized wicking garden ‘bed’
A wicking bed is a garden that acts like a giant self-‐watering pot. Water is topped up from below and the plants draw the water up through their roots – hence there is no evaporative losses.
Although wicking beds are the most water-‐efficient means of growing food, there are a couple of things to consider. A wicking bed is a closed system. This means that residues are concentrated as water is drawn up by the roots – for this reason – greywater is not recommended for a
wicking bed. However, being a closed system means that nutrients and water are not lost to the surroundings and maximises benefits to the plants.
So...how did I make my bed? Firstly, I did some internet research to find out what materials I needed and how to make it ‘wicking’ and not simply a raised bed garden. I found some sheets of corrugated iron behind the shed (but there are plenty at the Tipshop too!). I then went to the hardware and bought more than enough concrete liner (builders plastic), screws, and shade cloth. I found some 50mm pipe (a metre more than the diagonal length of the bed) and a roll of 10mm reticulation hosing at the Tipshop. I found a 10mm drill-‐bit at a lawn sale, bought half a metre of river rubble and river sand from landscaping supplies and a trailer of cow manure. I
also bought an elbow joint for the 50mm pipe and a plug for it.
Constructing the frame involved strengthening the bed-‐frame and sawing the slats in half and screwing them on the bed frame and the iron onto the timber. I thickly lined the garden frame with old newspapers to minimise the threat of puncture. The plastic liner was laid inside the bed. The irrigation system requires an L-‐shape pipe that lies diagonally along the bed length
with drill-‐holes throughout and a plug in the end, with the shorter vertical length to fill up from. The pipe was buried in a gravel sandwich with the shade-‐cloth laying on the plastic and 15cm of river rubble folded into it. This prevents the sand from clogging up the gravel layer. Then 15cm
of sand was layered on top. A drainage hole was drilled through the plastic, iron and bed-‐end and a short length of reticulation was pushed through. This prevents the bed from overfilling
when it rains and getting manky.
The soil layer needs to be 30cm deep. This was made up by mixing in the manure with local soil, compost and potting mix . Now it's ready to water. When water starts dripping out of the
drainage hole – it is full and ready to plant. Seedlings will need surface watering until they take root and the water starts wicking up from the bottom. I would recommend setting up some
shade cloth at this time of year to give the seedlings every chance to thrive in this burning sun. This is one way to make a wicking garden bed. Next step…. aquaponics.
