Compost piles require four things; a source of Nitrogen, a source of Carbon, water and air.
Nitrogen (aka “greens”)
Nitrogen is found in anything that is green and/or wet. Think kitchen scraps, fresh cut weeds, fresh cut grass clippings and even human urine. Nitrogen is akin to stepping on the gas, as it speeds up the rate at which your compost pile decomposes.
Carbon (aka “browns)
Carbon is found in dry compostable items. Cardboard, newspaper, dry leaves, dry grass clipping and straw. This is important to keep your compost pile from becoming too wet and turning anaerobic.
When a pile turns anaerobic it smells bad, but so long as you have enough Carbon, then your pile will smell earthy and like the floor of a forest. Add more carbon than you think is necessary and always have bagged leaves available next to your pile so that you are able to add a handful after every addition of Nitrogen.
For a compost pile to decompose there must be a certain amount of moisture involved. Remember, food scraps are loaded with moisture so if you have a lot of food scraps you may not need to add any additional water.
Ideally, the contents of your pile should feel like a wrung out cloth; damp, but not soggy. You want to encourage the aerobic (oxygen dependant) microbes in your pile if you plan to use the end result on your food garden.
Air is essential for keeping your pile at the right temperature as well as at the right moisture level. You can achieve an air-filled pile by having holes in the sides, top and bottom of your bin, by adding sticks to your pile to provide spaces, or bulky items such as wood chips or cardboard chunks. Sticks, in all honesty, will drive you crazy when you try to turn your pile, but it is a thought for those who aren’t interested in turning the pile.
The best way to add air is to turn your pile, and to do so as frequently as possible. Monthly at minimum. Having a second or third compost pile will help with this as you can novel out the contents from one bin and as you are adding it to the next bin over you are actively turning the pile and can adjust the Carbon/Nitrogen ratios as you go.
Top Tips from a Compost Lifer:
Put your pile somewhere close to your house so that you don’t have to make any grand efforts at getting to it in the back alley, or at the far end of your veggie patch. If it is accessible, you will use it and maintain it more often. You will also be more motivated not to let it go anaerobic (stinky) if it is closer to your living space.
Chop everything to help speed up the process. The more surface area that is available, the more access the microbes will have to your scraps and the faster the pile will heat up and biodegrade. Consider buying a machete to keep next to your pile along with a tree stump to use as a chopping board. This can be very therapeutic, or a great job for a child with lots of energy!
Add some garden soil, and more than you think is necessary. Your native garden soil will have all kinds of beneficial microbes that will help to speed up your pile. If your soil is more or less dead, therefore not adding any new microbes, add it anyway. In Calgary we have high clay content and this clay helps to hold onto valuable minerals making your finished product more mineralized.
The more different items you can add to your pile the better. Try all kinds of different ingredients, and don’t be scared to try new things; egg cartons, sand from your child’s sand box, egg shells, coffee grounds, or your neighbour’s lawn clippings
Have fun with it and feel the thrill as you turn your garbage turns into garden gold!