Wicking Beds

Is anyone familiar with Wicking Beds?  It seems like a smart and useful solution to me, especially for those of us with porr soil, little rainfall, and high evaporation rates.

Check out the info and let me know what you guys think:
http://www.waterright.com.au/wicking%20beds.html
http://www.waterright.com.au/wicking-bed-history.html
http://www.waterright.com.au/instructions.html
http://www.easygrowvegetables.com/html/wickingbed.html
http://www.instructables.com/id/Wicking-Beds/
http://www.maireid.com/wickingbeds.html

I posed this same question a few months ago and of my new raised beds this year have made two of the wicking type. I saw them on instructables. Still early and raining so once it gets hotter and drier I will be anxious to see the differences.

Thank you for bringing that to my attention! I may not use that technique, but it will be very, very good to know.

We have about 250mm of annual precipitation and we're subarctic, so water and heat are very important to us here.

This system offers a solution to both water shortage and lack of warmth potentially (with some addiional adaptations), but I wouldn't be happy with using plastic sheets in my garden. I want to eat the food that comes from it and plastic concerns me for a number of reasons, not the least of which being that it isn't supposed to go into my body. I think the system could be modified quite easily here though, to eliminate the need for a synthetic barrier.

We have lots of rich clay and sand and I think the wicking beds could be operational with a pond bottm-type set up- the kind that pigs can trample into place with the daily addition of clay and sand to the 'floor.'

What do you think? Obviously it wouldn't be completely impermeable, but it would be nearly, and watertight enough for the water to be wicked up before it seeps out.

It wouldn't be an afternoon project either, but I wuld be happier not cutting off the soil from the earth and also eating foods that didn't bed on plastic- even if it would take more work and time to accomplish.

Thanks for posting; I have more options for solutions to consider for next season! 

I definitely think a clay bottom could work.  You could also sprinkle some lime and/or cement and tamp the subsoil to get a fairly hard, water resistant container.

Concrete is another approach, like a ferrocement or earthbag container.

I also think that it depends on what sort of plastic you are using, its exposure to UV, the plants' ability to absorb chemicals, and all sorts of other factors.  The sad fact is that most folks get larger doses of plastics just through their drinking water than something like this would give you through a carrot.

But I think a workable solution could be found without using plastic.

In my area, we are dry for more than 9 months out of the year (no rain at all!), so a bit of plastic is a workable evil, so to speak.  I can't afford to waste or loose ANY water.

Are the clay and sand on your property mixed together, or are they found in separate deposits?

It sounds as though the pig method is particularly suited to separating sand from clay in-situ. If the clay is pure already, maybe traditional methods of tamping would be more appropriate.

I also want to second the idea of adding lime to the clay, in a controlled manner. I only know enough of the fundamentals to say it could work extremely well if done right, and would probably work OK even if done poorly; there are probably lots of sources of information on this.

Velacreations,

It does make sense to conserve water as a highest priority- even over an aversion to plastic... 

You're right too about plastic absorption from drinking water. We haul from a creek and our water will sit in our xyzchemical-free potable water plastic tank for a week before being empty and needing a refill. I imagine we're drinking some nasty plastic from that, but right now we're just not set up to do any better. I'd love to source some cedar tanks from nearby and use those insead, but we'll need some time to do that. I figure it's still waaaaay cleaner than city water. It must be because when we go to town, all of the city water smells to me like a sewer and tastes worse- not even very fragrant peppermint tea disguises it enough to stop my gag reflex.

Nine months without water is very long. We do have it for those nine months, but it's frozen and there's so little that when it thaws, it doesn't give us much to work with at all. Summer fires are blazing as usual and we even had to call in extra support from out-of-territory for back-up and forest-watering this year.

Anyway, I can appreciate the reality of little water.

Joel,

The clay and sand are layered and easily found in large deposits all over. Do you think that I could just dig up the topsoil and lay in a thick layer of tamped clay without sand? I'm not coming up with any reason not to do that, but I have no experience either. Would a simple rich clay lining be sufficient? It seems that it would be.

I have to learn more about lime; it keeps coming up, lol.

Imogen wrote:Do you think that I could just dig up the topsoil and lay in a thick layer of tamped clay without sand?

I think that would work great. It's possible some lime would make it work even better, but I'm not certain how much or with what technique.

I think sand could then be used as one part of a potting mix of sorts, to fill the space above that clay liner.

Imogen wrote:the city water smells to me like a sewer and tastes worse

Yech. I have some experience with small town water, but thankfully haven't experienced the worst of large cities. Oakland's water supply is pretty good, but in general it's hard to keep old, cracked water & sewer systems from cross-contaminating over such a large scale as a major city.