Size, heat, air, moisture, plus some additional factors.

Composting is the most natural process on Earth. In fact, that is what it is; earth. Both you and I will end up eventually as compost. That’s why there is life on Earth. It is a self-cycling, self-supporting process that gave this, our planet her unique properties (but that’s another subject).

Part 2: Putting the finishing touches your bin construction.

So, by now you should be the proud owner of a 3-sided, self-built, wooden box.

Now it’s time to get to the bottom line or at least the bottom of the bin.

Some advise a raised floor to allow passage of air (essential#3) but I’m ambivalent on this point. For one, this addition will gradually clog with old compost, secondly it makes a difficult journey for the ever-important visitors to your heap (essential#4 e.g. worms and other welcome guests) and lastly it just makes things complicated when emptying and turning. (It is also a waste of a pallet).

I find that because of the slatted nature of pallets, there should be sufficient means for the passage of air anyway.

At this stage it’s time to consider the method of access. There are various ways and means in which to approach this. It’s a question of balance; on one hand you need to be able to contain your, at times, anarchic heap of smelly, rotting garden and household waste but at the same time have to get to it, in order to turn it or to transfer it elsewhere.

I suppose that the easiest way is to secure your forth pallet to the main structure with light-gauge wire although, when the materials were available, I’ve made a sort of portcullis type of thing which was very practical but needed the additions of corner posts and frankly became a bit contrived. It depends entirely on your own imagination and resources.

One last point before we move on. If you can run to the extra expense, it is a good idea to line the inside of your bin with a mesh of some sort – coarse or finer grade chicken-wire for example, to keep your heap in order and under control.

You need now to consider the positioning of your heap(s). You may not think that a cubic metre amounts to much but as your interest expands on this fascinating subject, you’ll find that the area devoted to it expands proportionately at the same time.

In the past, I’ve ended up with five of these bins in a line, that’s 5 cubic metres or so which is quite a lot! Actually it’s not that much of a problem; organic rotting material reduces, eventually to about 5% of its original volume so if you want to have additional bins (which you will), then you just have to make them progressively smaller.

Compost heaps in general don’t tend to be very pretty in appearance but do need a degree of sun-light. If you can, try to pick a sunny corner, away from your house and out of view – or you could try growing a conifer screening-hedge around it. The clippings, if fine enough, can then go direct into the heap – I always try to aspire to an easy life, where possible…

…and, if you have been, thanks for reading. A bientôt!