As you start composting you will realize just how much kitchen waste can be saved from the dump, but as you’re adding in your potato peels, apple cores and coffee grounds, have you ever thought ‘what else could I add in here?’?
Well the short answer is almost anything that is unprocessed food, and that can include bones from your meals!
Now the long answer.
Composting is the process of turning any food waste into dark brown nutritious soil. Every piece of organic matter that goes through your house can potentially go into a compost pile.
Bones are no exception, but they do require some extra thought.
Most community compost pickups don’t recommend bones being added for a couple reasons. First, large beef bones could potentially hurt their machinery – those cow bones from soups can be fairly large. Second, bones can lead to vermin and other pests invading the compost area, something large-scale composters don’t want to deal with.
When it comes to your own compost pile you can definitely add bones if done the right way.
Size
Size matters when composting bones. Small fish bones can decompose within a couple months, same with composting chicken bones, whereas large solid beef bones may take years. If composting bones, either cut them down with something like Poultry Shears or use a hammer to crumble the bones into smaller bits. Those smaller pieces will compost much faster.
Cooked bones also break down easier.
Placement
To keep vermin (aka rats or mice) or other backyard pests from getting to those bones (which any raccoon will tell you are a delicacy), the suggestion is to not just throw the bones at the top of your bin, but bury them down the middle. Also having an enclosed bin or adding a cover to open bins will help.
Burying the bones deeper will also help the decomposing process start faster (see #3 below).
Use Hot Composting
Bones compost better in what are called hot composting – where the internal temperature of the pile rises to 141°F to 155°F based on a 2 parts carbon to 1 part nitrogen setup. At this temperature most weed seeds and disease pathogens die, which is also good for anyone worried about chicken bones. Hot compost piles should remain slightly moist, be turned every few weeks or so based on temperature going down (or just whenever you remember). Use twigs or sticks to add air pockets for the best process.
Alternatively, if your garden size permits it you can just dig a hole 2-3′ down in your garden and bury the bones there. That depth should keep animals from digging it up.
Be Patient
Bones can take a long time to decompose fully, but don’t let that dissuade you – bones are a great nutrient for gardens and compost.
When you start using your compost if there are still bone pieces, just throw them back on the pile (covered of course – see point #2 above). They will eventually break down.