straw Compost Bins
Straw compost bins are very large and generally more suitable for use on a couple of hectares of land, but if you have a large urban block that you are just starting to develop then this method is a good way to generate a lot of compost in a relatively short space of time.

Photo of nine straw bales laid out in a brickwork pattern
Nine straw bales laid out in a brickwork pattern.
Straw compost bins are also quite unique as the actual walls of the bin are part of the composting process. Basically it involves using bales of straw like giant Lego blocks to build the walls of your bin.  Any number of bales can be used depending on how big you want the bin to be, but in this example we will use nine bales.  The process is as follows :

building the straw frame
In an a  cleared area of your garden place a set of six straw bales to form a square on the ground.  Use the remaining three bales to build the back and sides of the bin up another level, making sure that they sit across the edges of the bales below to form a brickwork mosaic.   Hay, pea straw and lucerne (alfalfa) bales can be used in place of straw bales, but they are generally more expensive to buy.  A combination of some different types of bales
Illustration showing how to lay out straw bales to make a straw compost bin.
A. Place nine straw bales to form a brickwork pattern.

Illustration of completed straw compost bin.
B. Fill the hollow in the centre of the bales with compostable material.

Illustration of turned straw compost.
C. Cut and remove bailing twine and mix the semi composted bales in with the compost.
 might be useful.   

Filling the compost bin
Fill the bin with compostable material as per the usual process for compost bins.  If you are trying to generate a large amount of compost quickly you might want to accelerate the process by adding a lot of sheep or cow manure and loose bales of hay or pea straw.

Using the walls of the bin as compost
When it is full allow the usual time for compost to break down (somewhere between four and six months).  Now comes the unique part of the process.  You will notice that the actual bales have broken down considerably themselves, having been exposed to the elements for some months now.   So instead of removing the compost  you now cut and pull out the baling  twine holding the bales together.  Then, with a garden fork, mix  the partially broken down bales of straw in with the compost in the centre. Once this is done you can either spread it on your garden as a heavily composted mulch or let it compost down for another two or three months before spreading as finished mulch. 

It is also possible to empty the compost bins as per normal bins and repeat the process.  But by the second time around the straw bales would have definitely come to the end of their life as effective compost bin walls.

Of course this nine bale compost bin is just one of many sizes of straw bins that can be constructed.  It just depends on what your compost needs are and how many bales you have to construct the bin with.

WARNING  Do not build a straw compost bin on Couch grass as the Couch will work it's way up into the straw bail and be almost impossible to remove.