Wicking beds emerged from practical experiments aimed at growing food under drought conditions, first in Ethiopia and later elsewhere. The core problem was not the absolute lack of water, but unreliable rainfall and poor soils. By storing water underground and allowing it to move upward through the soil by capillary action, wicking beds created stable growing conditions. This article traces how the system evolved, why it works, and how soil biology—especially worms—became central to success.
History
I had been conducting research into ways of making more effective use of water when I was asked to visit Ethiopia to look for ways of growing sustenance food during times of drought.
What I learned very quickly was that the problem was not simply a lack of water. The real issue was the variability of rainfall. A break of just a few weeks at a critical stage—when seed heads should be filling—was enough to cause total crop failure and famine in the following season.
Crops would often look green and healthy, yet there was no growth. Locally this was described as a “green drought”. The plants survived, but they did not produce food.
It became clear that a better way of storing water, even for short periods, was needed. Some limited water was available from springs, but attempts to use this water with conventional furrow irrigation were unsuccessful.
The Problem With Furrow Irrigation
Ethiopian soils had been farmed for centuries and were badly degraded. They lacked structure and organic matter. When water was applied to a furrow, it would soak straight down at the head of the run, creating a bog.
No matter how long the water was applied, it would never reach the end of the furrow. The soil simply absorbed it vertically instead of allowing it to move sideways.
I experimented by concentrating the flow and irrigating many small areas in sequence. This approach, which I called micro-flood irrigation, was an improvement, but it was still not a complete solution.
Early Experiments With Plastic Liners
The next experiment was to bury a sheet of plastic film under the furrow to prevent water leaking straight down. This worked better, but only partially.
The water moved sideways along the plastic, but eventually it still leaked down into the soil. Losses were reduced, but not eliminated.
This led to a more radical idea. What if the plastic were shaped to form an underground pond beneath the plants?
At the time, this seemed risky. The assumption was that plant roots immersed above a body of water would die due to lack of oxygen and anaerobic conditions.
The Unexpected Breakthrough
Contrary to expectations, the plants did not die. In fact, they produced better and more productive crops than anything I had previously seen.
This result forced a complete rethink of how water, air, and soil interact. The water was not stagnant. Instead, it was slowly moving upward through the soil by capillary action, delivering moisture without saturating the root zone.
This raised an obvious question: why use a furrow at all when water could be run underground using a slotted drainage pipe?
Running water underground would reduce evaporation and create a much larger and more flexible planting area.
From Furrows To Underground Reservoirs
Using slotted pipes to deliver water underground worked well. The next logical step was to combine several sections into one larger underground reservoir.
This created a new concern. Plants would now be growing directly above a larger underground water body. Would this form a stagnant, anaerobic pond?
Once again, theory did not match reality. The system worked beautifully, with no sign of anaerobic conditions. Plant growth was strong and consistent.
Encouraged by these results, we began installing many wicking beds.
New Problems Appear
As the number of beds increased, new problems emerged. Some wicking beds performed exceptionally well, producing crops far superior to conventional methods. Others performed poorly.
The difference turned out to be soil quality.
Beds with excellent performance were filled with rich, well-rotted compost high in organic matter. Poorly performing beds had been filled with soil taken directly from the surrounding land—typically heavy, degraded clay.
Fertiliser improved growth in established plants, but germination remained poor. Seeds struggled to establish in these soils.
Germination Challenges
We tried placing a layer of commercial potting mix on the surface to improve germination. Results improved slightly but were still disappointing.
One of the challenges with wicking beds is that the soil surface remains relatively dry. This is a strength for water efficiency, but a weakness for seed germination.
We experimented with overhead watering during the early stages to help plants establish. However, this introduced new problems and undermined many of the benefits of the system.
Eventually, we decided to persist with underground watering even during germination.
Why Watering From Below Works
Watering from underneath offers several important advantages. The water is continuously moving upward, which prevents stagnation and maintains oxygen exchange.
There is far less soil compaction than with overhead watering, and evaporation losses are dramatically reduced.
However, for this to work well, the soil must have good wicking properties. Poor soils simply do not move water effectively.
The Role Of Worm Castings
Through further experimentation, we discovered that worm castings outperformed every other soil medium we tested.
Beds rich in worm castings showed excellent germination, strong early growth, and vigorous root development. The structure of worm castings allows water to wick efficiently while maintaining air spaces for roots.
This discovery led directly to the idea of turning the wicking bed itself into a worm bed.
Worms continuously process organic matter, improve soil structure, and produce castings that enhance both water movement and nutrient availability.
The Wicking-Worm Bed Concept
A wicking-worm bed combines underground water storage with active soil biology. Organic material feeds the worms, worms improve the soil, and the improved soil enhances wicking.
The system becomes largely self-maintaining. Water use is efficient, plant growth is stable, and soil quality improves over time instead of degrading.
This approach directly addresses the original problems observed in Ethiopia: unreliable rainfall, poor soils, and crop failure at critical growth stages.
Moving Forward
Many people are now interested in experimenting with wicking beds and wicking-worm beds in gardens, farms, and community projects.
Instructions for setting up wicking beds are available on this website. The system can be scaled from small garden beds to larger food production areas.
The key lessons are simple: store water underground, keep soil moist but not saturated, and let soil biology do the hard work.
If you have questions or would like guidance in adapting the system to your own conditions, you are welcome to contact me by email.
email: colinaustin@bigpond.com
