This is an update on the wicking bed systems I'm trialling.
Some points I've learnt from recently viewing the DVDs from Colin Austin:
1. The beds need to be deeper...
...I suspected this and will be building the beds up as raising the sides. Still working on how. Considering an extra row of sleepers from around the yard. Combining this with small bird mesh sides with a shade cloth lining to cut down on the evaporative effect of the wind here. It would be best to dig deeper into the soil but that's not possible in most of our yard...there's a rock layer down there!
2. You may like to include charcoal in the bottom 'pool' layer, this is added to 'sweeten' the soil. This doesn't seem to be necessary and I haven't found any need to yet but is something to consider if you are concerned about the bottom wet area acidifying. Perhaps in higher rainfall areas.
3. You fill the 'pool' layer completely to saturation when watering this helps to expel the old stale air from the area and as it dries out fresh air takes it's place. This is necessary in my dry region but may not be so crucial in wetter areas, or during 'wet' seasons.
4. Don't water from the top...this layer remains quite dry and should be covered in a 'worm' feeding mulch. I have been watering from the surface as the plants, mainly sweetcorn seem to need extra water in the heat, when the beds are deeper this shouldn't be necessary.
5. It's the (compost) worms in these beds that actually keep digging and improving the soil...I did wonder what happened at the end of each season to the soil. So you have to feed and look after your wormy workers.
6. The beds are based on the flood and drain system which is a preferred irrigation method but far too costly in regards water use and evaporation. These beds flood from beneath so evaporation is reduced.
Something else I've realized...Don't let your chooks in or they'll eat all your worms!!!
So far the local smaller bird population (mainly pesky blackbirds) have left the mulch on these beds alone but that may be because they are busy in my mulberry tree at the moment.
On the Waterright site there is a PDF called "Shade House". This is the article that was printed in Grass Roots magazine No 182 last year. That's where I first read about these beds and also refers to an article in a previous issue (No. 178) that I'd completely missed. In this version (in the pdf) the author cuts the drainage pipe in half, uses raised beds and has built an enclosed shade house over the beds. That would keep the birds out!
There seem to be a few variations on the main theme of this system. Including the plastic 'box' balcony version which I'll be trying soon to replace the polystyrene salad boxes under the pergola. These at the moment have the rechargeable water bags in them...while these are keeping the plants alive they don't appear to be thriving but then again 'alive' in this heat is better than dead.
I'm also considering some wicking boxes for growing tomatoes in the little hot house over winter.
I hope others take up the challenge of these beds and for detailed information I would suggest you read the Watterright site thoroughly.
Link to my other Wicking-bed posts: