Build a Wicking Bed Garden for Drought Gardening

1. Build a wicking bed
A wicking bed – not your average garden bed
Which way does water flow? Up! In a wicking bed water moves from a reservoir at the bottom of the
garden bed through the soil to the top, watering the roots of the plants from below. The water
moves by ‘capillary action’ – just like fuel moving up the wick of a kerosene lamp.
The plants don’t need overhead watering - you just keep the water in the bottom topped up by
filling the white pipe coming out the top of the garden bed. Fill it just until water starts to flow out
the overflow pipe on the side – this means the reservoir is full.
Why a wicking bed?
 Wicking beds use up to 50% less water than conventional vegie gardens as less water is lost
through evaporation.
 It’s low maintenance - plants have less risk of over-watering or under-watering.
 Plants get exactly the amount of water they need and their roots stay cool.
Build a wicking bed in a few easy steps
Step 1: Buy or build a structure for the raised garden bed, such as using two timber beams to a total
height of 40 - 50cm. Drill a hole at the bottom end of the lowest beam. This will be where the
overflow pipe will come out.
www.veryediblegardens.com

2. Step 2: Lay a plastic or rubber liner inside the bed. Make sure that no sticks or stones can cut
through the liner. If the bed is on a soft surface, you should dig down into the original soil 5cm. If you
are on concrete or pavers don’t worry – the bed will still work fine if the liner sits on the original
ground level. If in doubt add a cushioning layer of sand 1 or 2cm thick. Now lay the liner inside the
bed carefully. You can leave it going right up the sides of the bed to trim later, and you can staple
the liner to the inside walls so long as the staples are higher than the top of the first beam.
Step 3: Assemble the inlet, overflow and drainage outlets using PVC pipe, according to the diagram
below. The overflow pipe goes through the plastic liner and needs to be sealed well with plumbing
glue and a metal hose clamp to avoid leakage.

3. Step 4: Add pea gravel, to about 20cm deep, again on a cushion of sand if you’re concerned about
perforating the liner. This forms the reservoir to hold the water.
Step 5: Fill the bed with water using a hose in the inlet pipe until water flows out the overflow.
Step 6: Add a layer of geotextile fabric over the pea gravel, taking care to wrap the fabric up the
sides of the bed so that no soil can come into contact with the pea gravel.
Step 7: Fill bed with soil. The wicking bed is now ready to use! Plant out with vegies and herbs, as
you would a conventional raised bed.
Maintenance: Keep the water levels topped up using a hose in the inlet pipe. To remove salts, every
6 months you will need to drain the bed using the drainage pipe and refill the bed with clean water.
To buy raised beds and assembly go to www.veryediblegardens.com or call 9005 6070
For more sustainable gardening workshops go to www.mysmartgarden.org.au or call 9932 1142