There are thousands of articles about composting on the internet. Many of them have very detailed 'how to' instructions on what not to do. In reality though, composting is no more difficult than following a recipe in the kitchen - easy as pie you might say!
During my horticulture studies I completed a unit on organics and part of this involved a detailed study of the bacterial and fungal processes that turn a pile of waste organic matter into that lovely rich black gold known as humus. I will not bore you with all the scientific descriptions here but I do have a step by step photo gallery that might help new composters to understand just how simple it is, and how to get the best results.
Basic rule of thumb states that anything once living can be composted. However I will add the proviso that if you put meat and dairy products in the compost; A) it can smell awful, and B) you may well end up with rats and mice moving in too - so if you live in the city this may not be a great idea! Many articles claim that onion and citrus should be kept out but I routinely compost both and have no ill effect. Some things such as onion peel and corn cobs can take a long time to break down and may need to go through the process more than once.
With that said - here are the pics!
Small is good!
Composting is most efficient when the ingredients are smaller, so you should roughly chop the material before building your pile. Especially the big thick stems of vegetables such as cabbage and cauli etc. They do take a very long time to break down, but this is shortened by making the pieces smaller. They don't have to be tiny - just don't be throwing whole cabbages in there!
Even mix of 'green' and 'brown'
To stop the compost pile turning slimy and stinky, you need to make sure to have a good even mix of green and brown. For those not sure - green is the leafy green garden waste, kitchen scraps, coffee grounds, lawn clippings etc, while brown could be cardboard and non shiny paper, dead leaves, shredded branches and bark, egg cartons, remember to shred and chop to maintain even composting. Many people use a compost bin simply as a collection/storage bin for waste, and that is fine, it will break down eventually - but to make sure you get really good results it is best to gather up enough waste to fill the bin in one go. This allows it to get hot enough to efficiently compost without wasting all those good nutrients.
If it goes wrong......
This barrow load is from one of those black composting bins that you can get cheap - it didn't get enough air throughout the process so ended up a smelly rancid nasty mess. So as not to have it wasted, I mixed it evenly with the appropriate 'proper' composting ingredients and it all ended up beautiful - so do not despair if your first attempts do not go according to plan.
Let it breathe!
Mixing all the different ingredients evenly will help to ensure that the pile gets enough air - compost needs air and moisture to work. You can see that my compost bins have open slats that allow air in - and although we do cover it with a tarp (the lid is a work in progress!) some rain does get in.
Just add water!
You need to check the moisture levels from time to time. A good compost pile will be moist - damp but not dripping. Best way to check is to take a handful and squeeze it in your hand. It should leave moisture in your hand but water should not run from it. For the squeamish - you can wear gloves!
I have a soil thermometer to monitor my compost - it isn't particularly accurate but you can see here that the needle is reading well off the available scale. This is an excellent indication that the bacterial processes are taking place. Your compost should feel hot for several days once it starts working.
Turn, turn, turn.
When you compost has been cooking for a couple of weeks it could be in need of more air - so a gentle turn with a fork is a good idea. This allows more air pockets to be incorporated and you can assess whether more water is needed at this time.
After 2-3 months you should start to see something resembling compost, rather than a pile of waste! A stable compost is finished when it no longer heats up when stirred, and looks like good garden additive rather than breaking down scraps. By 6 months It should be perfect to go on the garden, although if you have new plants and seedlings you may wish to be careful in case there is still some heat. No point burning them when you are trying to do them some good!
This is a very basic description of what happens, but it should hopefully get you started on the road to being a home grown composter! Any questions you may have - message me via our Facebook page or send me an email and I shall try to help as best I can. It truly is one of the best things you can do for your garden and it means you don't have to take all that garden waste off-site - you can process it yourself and end up all the richer for it!
Happy Gardening Folks!
I'm Kimberley, and I live in the beautiful South Island of New Zealand. I am very passionate about growing strong healthy plants that enrich us and our environment. Welcome to my place - feel free to look around!