The best way to decay

I have a large backyard by local standards. Our property is 900sqm and the house etc would probably only cover around a third of that area. So there are plenty of trees and shrubs competing with a fair swathe of grass for the remaining space, all of which yield a fair amount of what some people call "garden waste".

Inside, we eat fresh fruit and vegetables on a daily basis and are producing a steady stream of "kitchen waste".

But of course it's not waste. It's a resource which I want to convert into natural fertiliser for enriching the soil and growing healthy food.

My neighbour generously provided me with one of those simple black plastic open-bottomed compost bins which he said was "surplus to requirements". For the last couple of months I've been feeding it with material from both the garden and the kitchen, turning it all over occasionally and adding a bit of water now and then. There's certainly something biological going on in there... the volume of material keeps shrinking and at times there have been different kinds of larvae and/or worms visible. But I'm not convinced that what's being produced is anywhere near as useful for fertilising my veges as I was hoping for.

The same neighbour also loaned me a book on composting which suggested that making compost effectively requires a lot of material to be combined in exactly the right proportions all in one go and then carefully tended. It was like baking a soufflé or something. And the fellow who gave the talk on BioChar a few weeks back implied a similar thing when he mentioned that "hot composts" are too hard to do right in a regular-sized back yard.

So what should somebody like me do? What about people with smaller yards, or mere balconies and courtyards? Well here are a few options:

BioChar bloke showed us pictures of a method of "cold composting" he was experimenting with, which involved digging a series of shallow pits which you would fill up one by one with whatever material came to hand before moving on to the next one. The theory is that by the time you filled up the last one the first would have decomposed to a degree which made its contents useful elsewhere in your garden and the cycle could continue from there. It still takes up a fair bit of space but doesn't require any financial investment to get started.

Part of the reason that "hot composts" require so much material and effort is that they need the bulk to produce and retain the heat, and they need frequent turning over to ensure proper aeration. There's a fancy compost bin on the market aimed at the suburban non-gardeners like me which uses a combination of insulation to trap heat and an innovative central air tube to try and get the benefits of hot composting without the effort. And it gets a very positive review (link to PDF) from a reputable Australian gardening club.

If you don't have a garden or a large family to produce enough waste to feed a large bin like that, then a worm farm could be the way to go. I was astonished to find that you can buy not only the farms themselves but also boxes of live worms from my local hardware megastore. These commercial kits are relatively cheap (compared to the fancy compost bin anyway) but I've seen instructions in various places for how you could build your own from relatively common bits and pieces.

Worms produce a different kind of fertiliser to compost, and you have to be a little careful with what you feed them (they really don't like onion or citrus, I hear) but if you're growing in pots on a balcony or in a courtyard it's pretty much an ideal solution.

I'm probably going to persist with my current compost bin for a little longer and see if I can't make anything useful of it. If not... I'm tempted by worms because they're cheap, effective, self-renewing and probably something the kids would enjoy. The fancy bin is attractive but I'm not sure if buying another new plastic thing is really the kind of solution I'm looking for.