Let’s just say I’ve been on holidays… for a year. But having returned to Alice Springs, I’m straight back to creating projects the Underground Permaculture way. There are two ideas behind the UP way:
- Everything you want to grow starts underground. That’s arguable as a practical statement, not a scientific or philosophical one. You can grow other ways, but it can’t be self-sustainable without the underground community of healthy living soil.
- “Everything I want to do is illegal” (quote from Joel Salatin). Believe it or not, acts of true sustainability are often illegal. There are forms of ‘sustainability’ that are encouraged by government and commerce (when there are products and services to sell and taxes to collect), but taking responsibility for housing, energy and resource cycling needs by households and communities is often deemed illegal to protect commercial and taxation interests.
Since coming back to town I have been making myself useful in a number of ways. Where I have been living, in exchange for my host-friend’s hospitality, I have been working on projects to increase the food growing capacity of their house-block. I’ve revived a dormant wicking bed and planted tomatoes and basil, and watching some self-seeded volunteers grow up in between. I’ve planted some fruit trees and dug in an ‘open wicking bed’ to help irrigate them, planting a living mulch cover crop which will be superseded by more productive perennial species after the summer heat has gone. And we’ve planned and begun building a ‘chicken-tractor / lawn-mowing-egg-mobile’ system (which obviously needs a better name).
I have also begun volunteering with Heritage Alice Springs at the Pitchi Richi site. After some initial renovations, I plan to move into a small cottage on the site. There is a small group of volunteers who are developing plans to renovate/restore/reopen etc. Definitely a ‘watch-this-space’ for more developments, or locals could come down and join in.
Other jobs and projects are popping up to keep me ‘busy’ (relatively speaking!) Having restarted posting on this website, I will keep it updated and start posting specific details of the projects undertaken, tracking their progress and effectiveness. Feel free to steal ideas, keeping them ‘open source’, use them creatively, feedback info and results of your endeavours and participate in a growing food revolution in Alice Springs and beyond!
I’m not gonna post too much about these. If you google it, you’ll get about 107,000 results in 0.21 seconds. To be clear, from here on in I and going to be talking about closed wicking gardens (as opposed to open wicking gardens here).
I participated in my first wicking garden build during my PDC (permaculture design course). There was subsequently some debates about their efficiency, and even the principles behind how they work. I have since done plenty of tests and experiments and can confirm with confidence that they work, provided you check some important factors in the build. So here are what I consider the ‘most left-out tips‘ when designing and building a wicking garden bed:
- Make sure it doesn’t leak. It might be obvious, but whether yours is in ground or above, once you’ve put it all together and planted it out, you do not want any doubts in your mind about whether the water storage is leaking underneath everything you’ve just built. You won’t want to pull it all apart to check, and it is really hard to tell if it is leaking by the water consumption (unless it is a catastrophic leak!) This is especially important if using builders plastic as your waterproof liner. Some sand and geo-textile fabric beneath (and maybe above too) to prevent puncture from rocks, sticks, etc, and root invasion, may be a good investment to protect your water storage during and after the build. If you have used a bath tub or similar, be very sure of the long-term seal of your plug before filling with the wicking medium.
gravel wicking tests
- Speaking of wicking medium…; this is the gravel or mulch you put in the water storage part of your wicking bed and it creates open spaces for water storage and close spaces to wick water upwards. When choosing your wicking medium, you have to know if, and how well, it will wick; how far will it wick water up against gravity? The only way to know is to do a test. Put a small amount in a bucket or jar to the depth you want to use it in your garden bed, with a pipe to the bottom. Put some cloth over it, and some soil on top. (You’ve just made a miniature version of your wicking bed. For a complete test, use a container big enough to hold the depth of gravel and the depth of soil you want to use in your garden bed. 200-300mm seems to be the accepted workable depth of each.) Fill the jar with water up to the cloth through the pipe and put it on the window sill. It will start wicking and continue until the water is gone. If it doesn’t start, moisten the soil a little to help kick-start it. If it starts but then stops, that is probably the maximum depth that wicking medium is capable of lifting the water. You can use it to that depth or choose and re-test another medium. If you are using gravel, try different types of stone and different sizes. (Sandstone will wick water through, as well as between, the stones, but will it disintegrate over time?)
- Your soil is important for growing plants, just like any garden. Being a closed system, and usually a raised bed, you soil has to be great quality – like a potting mix. It needs to be light, have plenty of organic material, and good structure. Don’t put in the native soil, especially in central australia. It will have a tendency to collapse and go hard, with no air or water holding capacity.
- Know the capacity of your water storage. The best way is to time the first fill, then time a filling of a bucket. Using the times and the known capacity of the bucket, you’ll be able to work out the capacity of the reservoir. You will then know how long to put on the tap (or timer) to fill your reservoir, and how much water you garden uses to compare its efficiency with other gardens.
- Finally, mulch. The mulch is important, especially in arid areas where evaporation exceeds precipitation (more moisture is taken from the soil than put in via natural means). If you mulch effectively, the only water loss is the transpiration of the plants. One last thing: when designing your garden bed right at the start, allow an extra 100mm of wall height to hold the mulch in the garden.
This wicking garden bed (above) is a small system made of mostly re-purposed materials. It has a 2nd hand bath underneath, dug into the ground. The raised bed is a simple timber frame covered in shade cloth and filled with the family’s compost. It stays moist all the time, even on the hottest Alice Springs days, and will completely empty the reservoir of water before the soil starts to dry out. It is the middle of summer and we’re still doing some measurements, but at a rough estimate, and if there’s been no rain, we are refilling it with maybe 80 litres of water a month!