Everyone, well, almost everyone I know has tried to compost - 'tried' is the operative word here...many have tried to compost but failed miserably. What they envisage to be the end result ie that lovely crumbly dark, sweet smelling earthy ideal hasn't been accomplished, but instead, what's happened is that they've ended up with a sopping wet, putrid, moldy looking mess that looks nothing like it. As a result, they throw their hands up in dismay and think to themselves - it's all too hard, I'll just leave it to the experts. I admit that I was like that and my initial futile attempts at composting was just as uninspiring. What kept me going? Well, after 3-4 attempts at it, I did it and after that, I've kept at it and my garden is loving me for it!
The secret of making compost
So what's the big secret? I soon realized that making compost wasn't just a matter of dumping all the materials in and hoping that by some magical touch of nature it will come good in the end. It's much like baking a cake. You need the correct ingredients in the correct proportions to make compost. In other words, it takes dedication on your part, you can vary it to a certain degree but if you want to ensure success in making compost every time, then you should adhere to a few general rules.
Rules for making compost
These rules were established in 1947 by a British Agricultural Officer in northern India. In his classic gardening book, An Agricultural Testament, he spelt out the methods for the construction of compost heaps that we all use today. He said you need to have a balance of 4 things in making compost:
- Air supply - if you don't have adequate air flowing through the system, you will end up with that slimy foul smelling mess that we all get when we leave out the 'regular turning' of the mix or if we heap on too much green matter eg kitchen scraps and lawn clippings.
- An equal ration of carbon and nitrogen sources. Too much nitrogen sources and you end up with 'compost' that is foul smelling and overly moist, too much carbon sources and you end up with a slow decomposition of the materials and your compost never seems to 'be ready'.
- control the acidity of your compost heap. This can be done by adding dolomite or lime.
- control the moisture level of your compost heap. A compost heap must be free draining. Don't make the mistake of putting plastic sheeting underneath the compost heap to make it look 'neater'. This would inevitably result in the moisture within not draining freely and you get a slimy mess.
The how tos of making compost
There are various ways of making compost. If you have the luxury of a large garden, then dedication of an area for compost making would allow you to make compost heaps. In most large gardens, you will have room to have an area set aside for 3 compost heaps - one compost heap that you are building the layers for, the second that's in the cooking/turning phase and a third that's all done and ready for you to fork out to the garden.
Making compost by using the layering/heap method
Start with a 'mattress' of small branches. This elevates the compost layers above and allows air to circulate through the compost heap. Cover this layer with a layer of carbon material like hay, dry clippings, shredded cardboard,paper, sawdust and other prunings. Sprinkle some dolomite or lime on top. Then add a layer of nitrogen rich material like manures, kitchen scraps, comfrey leaves, blood and bone. Again sprinkle with dolomite and lime, and finish off with a layer of garden soil. You can opt to start layering again ie carbon/nitrogen/soil and once you are happy that it's all done, then cover it with tarp or carpet underfelt to prevent the rain from getting it too soggy. After the compost heap has heated up, turn it to aerate the innermost sections. Don't be surprised if you see heat steaming out of your compost heap. A properly made compost heap will reach temperatures of up to 70°C which is the reason why you should NEVER add earthworms into your compost heap - they will cook!
Making compost using compost tumblers or compost bins
What if you don't have the room for a compost heap? Let's face it, a compost heap isn't the most aesthetically pleasing sight for a garden. You can opt then to use compost tumblers or plastic compost bins. Compost tumblers are great because they allow you to 'turn' and aerate by 'tumbling'. They don't take up a lot of space and can easily be hidden behind a bush or in the side alley of a house where it is less obtrusive.
Compost bins are also a great alternative to the heap as it looks more contained and less 'messy'. It works the same way as the heap. Turning is more difficult however - you can use the compost aerator tool above. The compost bin on the right is the Pyramid composter and the lid is great in that it allows sufficient rain water to get into the compost bin without leaving it sopping wet.