I spent a lovely afternoon on the farm yesterday making our winter compost pile. Compost is at the heart of organic farming – without it, it is virtually impossible to grow vigorous, healthy, delicious vegetables. We’re hoping to get a composting system going next spring so that we can feed our fields with own recycled organic matter (vegetable scraps, grass clippings, weeds, cow and chicken bedding, kitchen scraps, etc). a great way to quickly produce high-quality, pathogen and weed seed-free compost is to make ‘hot’ piles – ones that reach a temperature of up to 140 degrees F. The community of earthworms and microorganisms (mostly bacteria) that break down organic matter is more diverse at higher temperatures – there is a whole slew of thermophilic bacteria that thrive when piles get hot. Maintaining hot piles, however, requires some work.
1. The pile must be built all at once. Unlike cool composting (which is what our winter compost pile is), you cannot add to your hot compost pile every day. It won’t ever reach the desired temperature.
2. Hot piles work best at a minimum size of 3 feet wide x 3 feet long x 3 feet tall. At this size, the pile has enough mass to heat up, and is still small enough for adequate air circulation.
3. You have to turn the pile. While turning is an important part of making any kind of compost, it is especially important when making hot compost. (If you simply layer leaves, kitchen scraps and other organic matter in your backyard and forget about it, though, it will, eventually, decompose.)
I’m pretty excited about hot composting, and looking forward to doing some of it next summer, when we have a whole lot of organic matter around the farm. For now, since we don’t have a whole lot of organic matter, and we mostly just want a place to compost our kitchen scraps, the cool pile that I started yesterday will work just fine. Cool piles are nice because they require very little maintenance, and you can add a little bit to them every day without worrying about the overall mass of the pile.
My first step was to pick a site for the new pile. I chose an out-of-the way spot on the edge of the woods:
Next, I raked away all the leaves from the area. One important aspect of composting is the carbon-to-nitrogen ration. A good rule of thumb is 30:1 carbon-to-nitrogen. Matierals high in nitrogen, or “green” materials, such as manure, kitchen scraps, and fresh grass clippings, should be mixed with carbonaceous, or “brown” materials, such as dry weeds, straw, woodchips, and leaves. As we add our kitchen scraps to this pile over the winter, we’ll cover each addition with a generous helping of leaves, which will keep our C:N ratio balanced, prevent the pile from becoming smelly, and deter pests.
With the site prepared and ready to go, I hauled over some old hay bales to make two side-walls for the pile. This will help us keep the pile from expanding. I decided not to actually build a structure for the pile, but having a defined area will keep it neat over the winter.
I layered the bottom with some fibrous brush, to provide air-flow at the bottom of the pile and to act as the first carbonaceous layer:
The next layer: kitchen scraps. We’d been dumping all our kitchen scraps in a haphazard pile on the farm. With a garden fork, I turned and mixed this clumpy pile, breaking up any matted, rotten vegetable matter. I then redistrubred the scraps over the new pile. You might notice a lot of big pieces – corn cubs, Brussels sprouts stalks, even a whole cabbage – in the mix. This is not a great idea. In general, the smaller the scraps you put into the pile, the better they’ll decompose.
On top of the wet layer of kitchen scraps, I covered the pile with a 3″ layer of leaves. The pile practically camouflages itself!
With the basic structure done, this pile is ready to injest all of our winter kitchen scraps. It won’t make the most beautiful compost in the world, and it will take a long time (at least a year, maybe more), but it is a good start. We’ll add to it all winter long, and through the spring. When it gets big enough – about 3 feet tall or so – we’ll cover it with some straw, call it finished, and leave it alone for the earthworms and bactiera to work their mircales.