The Wicking Bed - a Giant Self Watering Pot!

Have you ever heard of the Wicker, Wicking or Wicking Worm Bed? I was fortunate enough to do a weekend course several years ago with Alanna Moore - a master dowser            (http://www.geomantica.com ) near Castlemaine. As we are surrounded by trees, the roots tend to steal the water & nutrients from my garden beds.

"The wicking worm bed is a highly productive growing system which not only produces more food from limited water, but also recycles waste organic material to provide plant nutrient and capture carbon. The essence is to form an underground reservoir of water or pond contained by a waterproof container or liner below the surface of the soil. Plants are productive because they have a continuous supply of water and nutrients." Colin Austin

The Wicking System was devised by Australian engineer Colin Austin (ozzie ozzie ozzie oy oy oy), wicking garden beds (and wicking worm beds) are gaining popularity as a wonderfully water wise garden bed alternative.

Wicking beds have a number of benefits, both environmentally and horticulturally.  Firstly, it’s a fab set up for thirsty gardens (like vegie patches) in areas that have lower rainfall, or are affected by water restrictions.  Wicking beds also deliver the water were it’s needed (the plant roots), which minimises water wastage, and can also help to reduce the risk of  fungal foliage issues.  Also, wicking beds are said to be more effective at sequestering atmospheric carbon then many other traditional types of garden bed set ups, meaning it’s a win for us, and the planet.

     

Wicking beds water plants from below rather than above. This works by filtering moisture through a network of absorption tanks and drainage sand to take water directly to the roots – where it’s needed most. Wicking beds work like a big sand or gravel sponge as water moves from the bottom to the top and then wets the soil that the vegies are growing in.

Step 1.
Remove the soil from your existing 5x3 meter garden bed and then level and terrace the ground for the new beds, which must be completely level for even water distribution. Put a layer of soft-sifted soil on the bottom for cushioning —to protect the plastic from sharp objects (you can use sand instead), and create a waterproof bed with the 200um plastic sheeting. Make sure no sharp objects can cut into the plastic sheeting.






 Step 2. Add the agi-pipe, stretching 

the full length of the bed.

Step 3.
 Cover the bottom of the bed to just above the pipe with the screening rocks.

Make sure you have enough space left for soil plus mulch: 330mm (about 1.08ft)

Step 4.
Lower the PVC pipe to the bottom of the bed, and position it in the 'mouth' of the agi-pipe, then  cover the rocks with the shade cloth, to separate the soil from the rocks and pipe. Then drill a drainage hole at the opposite end of the bed, at the level of the screening cloth - or 330mm from the top of the bed.

NOTE: The water will wick up no more than 300mm through the soil, so the soil level should be 300mm above the water line.

Step 5.
Sift the old garden soil into the bed, removing stones, seeds, weeds, and roots.  Or buy good quality soil. This will save you time & your back.

Step 6.

Have you a pH soil testing kit? Might be a good investment. Add soil then add a generous mixture of organic compost, mushroom compost, lime, and blood & bone, –leaving a space at the top for mulch.

Alkaline pH 7 soil is perfect for above ground veggies. Most root veggies like a slightly acid pH soil, round 5.5 - 6.5 pH.

Step 7.
Fill the top with a layer of organic sugarcane mulch, and drill the drainage holes. When finished, add the water through the pvc pipe - test how long it takes to fill the bed to the drainage hole, and measure the water level in the pvc pipe, so you can know in future, by looking into the pvc pipe, when the water is low.

http://www.maireid.com/wickingbeds.htm

• Ensure the overflow/drainage hole or pipe (at the 300mm point) does not become blocked or non-functional.  Give this a good clean out every few months.
• Be aware that, as a closed system, everything you put into the bed stays in the bed.  Overuse of fertilisers (even some of our trusted organically derived ones) may see the soil sour fairly rapidly, leading to an increase in saltiness.  This is certainly NOT ideal for many of our productive vegies and herbs.
• Greywater (that is, water from the bathroom and laundry) should NOT be used in a wicking bed at any time
• Compost and soil mixture will need to be topped up seasonally, as will the mulch.  A good idea may be to lightly turn the top 300mm of growing area with a garden fork at this time, to “freshen up” the soil.
• Cover the open end of the PVC pipe (the water inlet) with a tile, brick or similar (old pair of pantyhose).  This will prevent mosquito larvae from hanging out in the tube or garden reservoir.