There are a lot of ways to make compost. Contrary to what some may think, not all methods work. The beginner is apt to have the idea that you simply throw your kitchen waste in a bucket and let it become rich compost. This will not work and will instead turn into a smelly mess because the “recipe” isn’t right. There is most definitely a science and probably an art to making good compost. The method laid out here is one that is simple and which most people should be able to make.
Fresh off a PDC course with Geoff Lawton, I set out to create the 18 day compost he introduced in class and in his “Permaculture Soils” DVD. It’s not the first time I have tried to make compost, but it is the first time I set out to make it with a solid plan that has been proven to work. After having read various sources about different setups requiring the construction of an enclosed area and not so clear explanations of the carbon to nitrogen ratio necessary to make good compost, Geoff’s explanation came as a breath of fresh air that left me convinced I could make good compost for the home garden. He describes it as a recipe and I think this is a very fitting analogy. It certainly makes the process somewhat familiar already for one who knows how to cook, so let’s run with this food analogy.
Make Compost- Quick
This method of composting is the fastest, with the finished product ready to go into the garden on the 18th day. Size is important here; the pile needs to be at least 1m3 size (1m x 1m x 1m). It can be larger, but anything significantly smaller than that won’t have enough mass to really heat up. The heat is from the reproduction of beneficial soil life, and all that sexy action is needed to yield a really quality compost that not only has nutrients, but is alive.
The creation of soil life is the greatest benefit of making compost yourself. However, making a pile this size does take a lot of material, which may not be available to those living in the suburbs. It also takes quite a bit of work to make compost this quickly, as it is necessary to turn the pile every other day until it’s done. This takes approximately 20-30 minutes each turn, adding up to about four hours of work total.
18 Day Compost Recipe
Pitchfork- preferably long handled
Tarp- approximately 3m x 3m
- 2/3 of the pile is your carbon material, which can be dried grass, hay, wood chips, dried and shredded leaves, and also other materials depending on what you have available.
- 1/6 is weeds from your garden
- The remaining 1/6 is your nitrogen source, usually manure from a variety of sources.
These are the basic ingredients which are a must have, and what we are shooting for is a 25:1 C/N (Carbon to Nitrogen) ratio. That’s 25 parts Carbon to every one of Nitrogen.
Optional ingredients which you’d do very well to add include:
- Compost activator, which can be dried comfrey, nettles, dead animal (really!), urine, or a bunch of other things.
- Charcoal, especially if you live in a tropical or subtropical climate. Crushed charcoal provides tremendous surface area for microbes to colonize.
- Kitchen Scraps and other organic waste
Spread a mat of carbon materials about 10″ thick or so as a sort of buffer, then start piling alternating layers of the manure and carbon on. Remember we are going for a 25:1 C/N ratio here- let that be your guide. There is sort of an art to making compost, so do your best to judge the appropriate amounts of material to lay down. It’s not necessary to get things perfect here as there will be plenty of opportunities to better mix the materials when we turn the pile. The pile should end up being a 1.5m tall gravity fall pile, as it would be close to impossible to make one that is a perfect cube with 1m sides.
Just Add Water- but not too much or too little
At this stage, give the pile a good watering. It takes around 5-10 minutes of watering. Check to see that there is sufficient water, and not too much water. Grab a large handful of material from inside the pile and squeeze hard with both hands. Water should _just_ drip out. You don’t want too little or too much water- just enough is ideal for the microbial life we want to encourage.
Cover and let simmer
Then, cover up the pile with the tarp and wait.
Turning the Pile
On the fourth day (day 1 is when you make the pile), give the pile its first turn. You want to basically have the material on the outside of the pile end up in the middle of the pile so that it gets a chance to be converted into compost. The pile should already be heating up, indicating that microbe are well underway in converting the raw materials into a great finished product. You basically end up rebuilding the pile next to the original pile. Cover with the tarp again.
Checking the temperature
Now, we will be turning the pile every other day until the 18th day. The pile should The second (day 6) or third (day 8) turn. We want the temperature of the pile to be between 55 and 70 degrees Centigrade, which is the ideal range for soil life to flourish. A compost thermometer is the easy (and expensive) way to check, but those of us who don’t have access to this equipment can employ the “Ow” test. It’s simple and consists of sticking your arm into the pile, up to the elbow. It should feel like a nice hot shower (55 degrees). Seventy degrees will apparently feel scalding and you will reflexively not want to stick your arm in there. Seventy is actually a bit hotter than what we want, but is okay. Fifty-five is ideal.
After day 6 or 8, the pile should gradually cool down. Keep turning every other day until day 18, and then use your compost in the garden!
Notes Pertaining to My Personal Composting Situation:
Making a pile one meter square requires a lot of material. For those making compost on a small suburban plot, it can be challenging to get enough biomass for the pile and it will often be necessary to bring in outside carbon and nitrogen sources depending on where you live. Here in the subtropics, I scrounged my carbon materials from the empty lot across the street which had just been cleared of a whole lot of pampas grass in preparation for building. This I got permission to take, and I did so using a tarp and lugging the grass across the street and up the steps of our place. It took many trips but the grass ended up forming a good portion of my carbon source.
One man’s junk…
I also engaged in some guerilla pillaging of the waste from the little park down the street, where branches had been cut and stacked. These were also procured through laboring in the dark, after work, and two large piles of leaves were taken along with branches and tree limbs up to about three inches in diameter.
Size of Materials
It’s necessary to shred these carbon materials, and for this I enlisted the help of a rented shredder/chipper which took three of us to carry up and down the steps. The rental was not cheap- around $70 USD including delivery and gas. After three hours of very noisy work, the wood, grass, and some leaves were shredded into material fine enough to be used for composting.
I procured a small plastic tub full of horse manure from my wife’s uncle, who runs a small horseback riding operation. I also used 1 bag of EM fertilizer consisting of cow manure and rice husks (kome nuka in Japanese) and 1/2 a bag of fertilizer made from cow and pig manure and peat moss.
All in all, significant labor and quite a bit of money went into this pile of compost. I think this way of making compost may be impractical for those who can’t easily grow a lot of biomass. I spent the effort and money on making this pile because I wanted to do it right and see the result. Perhaps I will be able to do it cheaper in the future- there’s still quite a pile of woodchips left and a few bags of leaves as well, probably enough to make another pile. I will be checking for sources of cut grass and hay, which should be a much easier source of carbon even if I have to pay for them- I will shred this material with hand tools instead of paying the cash to rent the chipper, which is way too loud when you have neighbors!
Having learned of the importance of soil life, I was keen to see the effects in the garden. This we will have to wait to see- I’m still on day 6 right now, and the temperature of my pile feels like a nice shower temperature!
Other Composting Resources: