In his passive solar greenhouse , Rob Avis of Verge Permaculture constructs wicking beds from food grade 1,000 L tote tanks . Each tank ( which makes two wicking beds ) is roughly $ 100 and is much more affordable than constructing a raised wooden box . In his DIY version Rob puts weeping tile into the bottom and up the side of the wicking bed to increase the reservoir capacity and act as a fill tube . Then , he adds enough gravel to cover the weeping tile . Landscape fabric is placed over the gravel to keep the upper level soil separated .
PHOTO COURTESY VERGE PERMACULTURE . to build a wicking bed is moderate , but it ’ s not the easiest beginner project to construct ,” says Angelo . “ If you ’ ve never built anything of the sort previously , I ’ d recommend building a smaller scale wicking bed before attempting a giant-sized bed that may take a few hours to complete . Websites , such as Deep Green Permaculture ( see resources ), offer fairly elaborate designs and images to show how to create a wicking bed .
ANCIENT TECHNOLOGY FOR A MODERN WORLD
Colin Austin of Waterright , Brisbane , Australia , observes that wicking beds occurred naturally over a billion years ago in deserts , where a layer of sand covered a clay layer . But Austin says it was the Aztecs who were the real inventors . “ They had a really nice system of a network of canals around their cities . They made a raft of rushes covered with a layer of soil to create the first and still the largest wicking bed system that the world has ever seen — feeding thousands of people in their major cities .”
Austin , an engineer , maintains that many drought and famine problems are caused more by erratic rain than no rain , and that wicking beds offer a possible solution to once again feeding thousands of people — sustainably — in many places around the world .
To get more out of your wicking bed , Angelo Eliades of Deep Green Permaculture suggests :
• Mulch . A thick layer of mulch up to 3 inches ( 7 cm ) deep keeps the moisture in the soil , prevents evaporation , keeps plant roots cool and conserves water .
• In-soil worm farms . A wicking worm farm can be constructed directly in the wicking bed to produce worm castings , one of the best-known fertilizers .
• Extra growing space . Put up trellises to grow climbing plants like beans , peas , cucumbers and watermelons . Attach this outside the wicking bed so the liner will not be punctured .
• Protective covers . Make a frame to support netting to protect the plants from insects and birds .
Anne Marie Van Nest is a past president of GWA and member of the Sustainability Committee . She is a freelance garden writer , teaches classes on tropical plants during the winter and is a greenhouse grower for Niagara Parks in Niagara Falls , Ontario , Canada .
An incorrect caption ran with a Sustainability column photo on page 18 of the December 2016-January 2017 On the QT . The caption should read : A permaculture garden in Wisconsin emphasizes edibles .