Wicking Beds: Water-wise Gardening Part 1
Updated: Mar 25, 2019
Spring is usually quite beautiful here in the Texas Hill Country - if we have one. There have been years where we really went straight from winter to 100 degree weather without much of a spring at all. However, we have been fortunate this year and are having beautiful temperatures in the 60s and 70s with a mix of sunshine and rain. Pretty perfect for starting a new garden project - the Wicking Bed.
Some of you may have heard of wicking beds before - there are many variations out there and I've been researching them for about a year and doing lots of planning. In our area (Zone 8A), we have extremely hot and dry summers that last and last and last...I've spent days out in the garden watering deeply in the mornings only to find plants wilted by the afternoon. Our neighbors' wells have gone dry some years. Being outside for more than five minutes in July and August can be miserable. Drip irrigation hoses would crack in short amounts of time, and watering by hand is a huge time expense (and rather inefficient due to evaporation). It's quite disheartening at times, and I wanted to find a solution that would be more water-efficient, time-saving, and ultimately, better for the health of my garden.
I believe in systems thinking, and so I knew that to improve the outcome of my garden, focusing on the system as a whole would be the best way to address my watering needs. I believe that I have found that system and will share it with you here. This blog post will be a multi-part series because of the magnitude of information, but I hope it will all be helpful and user-friendly for anyone interested in water-wise and efficient gardening.
When planning for a garden, where should you start? Always with the soil. If you haven't had a soil analysis done, I highly recommend it. You can go through your county extension office, or simply buy a test kit on Amazon. Easy enough, and it will give you a wealth of information on how to supplement or amend your existing soil. My soil is rather poor, rocky, and very high in calcium due to the limestone content. After digging through about a foot of caliche, you pretty much hit solid rock. Composting to create a more acid soil environment is helpful, but having enough organic matter to match the scale of our garden is simply not feasible at this point. Enter the raised-bed garden.
Raised beds have worked for us in the past because it allows us to add soil, compost, and any other amendments without competing with the existing soil. They are also a lot easier on my back. If you build them high enough, they also become more accessible for people with some disabilities, which is extremely important to me. There are many benefits to them, and I've been using raised, square-foot garden beds for years; but I still needed a more efficient watering system.
While researching solutions for watering, I came across the story of a man named Colin Austin, a philanthropic Australian who created the wicking bed system. In Ethiopia, the famine, starvation, lack of rain, and low nutritional content of food were killing their people. Mothers were so nutritionally-deprived, they couldn't even make breastmilk for their babies. Austin developed a simple way to grow food with very little water, and helped the people grow nutritious food and ultimately, survive. Austin freely shared his technology, having no desire to profit from his invention. He eventually took the design back to Australia, (where they also have a hot, arid climate), and wicking beds became extremely popular.
The basics of the bed are this: A raised bed has a perforated pipe that runs along the bottom that, when watered from a pipe that feeds it in the top, fills a reservoir (gravel or something water-retentive) with water. Then, capillary action pulls the water up from the bottom into the soil and feeds the plant roots.
Essentially, watering from the bottom has several benefits:
1) Stronger, deeper root systems for plants.
2) No water evaporation from the sun.
3) Water is used more efficiently.
4) Fertilizer and nutrients are retained and not washed away.
5) Plant leaves are not exposed to water and therefore, less susceptible to mildew and disease.
Wicking beds can become water-logged, and so are not ideal for perennials or plants susceptible to root-rot. However, for an annual vegetable garden, they are a good fit. In my next post, I will share how we created our own wicking bed here at Great Oaks Farm.
What water-wise gardening solutions do you have? Share in the comments below!