MEG is a water wise garden with individual wicking beds.
A wicking bed is simply a huge version of the self-watering pots that were popular years ago, where a reservoir in its base stores water which is then drawn up (or ‘wicked’) by the plant roots as required. The main advantage of a wicking bed is that it doesn’t require daily watering, even if the temperature reaches 40c, and it stores excess rainwater instead of allowing it to drain into the earth under the bed.
Essentially each plot is lined with a polymer membrane liner and with a geotextile fabric separating the gravel/water reservoir below and the sandy soil above. Great care must be taken not to damage or puncture the liner or the plot will not function. Water diffuses up from the reservoir into the soil and plant roots are always in contact with moisture. Even during the hottest weather, plots need be topped up weekly. Overhead water is generally only needed for seeds or seedlings. Fertilizers and worm juice can be added directly to the reservoir through the top up pipe.
Snails like the cool moist conditions in the underground pipes so it is important to keep the pipes capped or otherwise covered.