(This post requires a disclaimer. Compost is my favorite gardening topic. I get extremely passionate and opinionated about compost and I can talk about it for hours. You don’t have to indulge me by reading this whole post. Really, you don’t. Just never bring it up when you see me in person or I just won’t stop.)

About once a year we dig up one of the garden compost bins at the back of the yard. In the photo above, you can see that I have started to dig out the right bin. The sieve is necessary to separate the compost – which at this point is loose particulate – from the undigested matter such as rocks, small sticks, bits of garbage, root balls, and bulbs. The whole process is very labour intensive, as the sieve is loaded with a few shovels of dirt, then shaken over the wheelbarrow or bin. About 85% of the material passes through the sieve, and the rest goes into the yard waste.

The end product (shown in the bin above) is quite uniform and ready to put in the garden. Most of it will probably be used to replenish the vegetable boxes later this fall or early spring.

By alternating garden compost bins, we can add new material to one bin while the other one rots. This means that most of the material in our yard rots for only one or two years before it gets cycled back into the garden. There are many things that don’t compost in that relatively short period of time including: hard wood and large branches, cedar boughs, hard pine cones (from the larch, for example), orchid roots, fruit stones, most types of evergreen leaves such as rhododendron. There are also a number of things that we don’t put into the compost because they are unpleasant, unhygienic, or induce the “yuck factor” such as holly leaves, dog poo, or dead things. We now just put all of that into the yard waste or bury it.

The food compost is not quite as straightforward. We only have one bin, and because we are adding new material almost every day, the food compost doesn’t have the same length of time to rot as the garden compost, and new materials get mixed in with the old. Last summer I dug out the bottom half of the compost bin, which was (in theory) the oldest material, and it was like thick, sticky mud, studded with avocado pits and fruit labels. Based on the large number of avocado and mango pits in the mix, you would have thought that our entire diet consisted of those two fruits alone. This demonstrated that composting is efficient and able to condense a large amount of material down into a small volume, and avocado and mango pits don’t compost very well. In the end I dug the mostly-digested food compost (minus the pits and the labels which I mostly picked out) into the garden compost to rot for the winter. This was a good strategy – and maybe it balanced out the pH or something – because that was the compost bin that am digging out now.

As a result of all the many hours I have spent digging out and sieving compost, I have some very strong rules for what can go in the food compost and what can’t. Here they are….

Chrystal’s rules for what doesn’t go in the compost

1. Avocado and mango pits.
2. Peels from some exotic fruits including avocado and pineapple. Maybe it just doesn’t get warm enough in our climate for these to compost properly? In contrast, we always put whole pumpkins in the compost after halloween and they rot down to nothing.
3. Silk teabags and string.
4. Fruit labels. Arrggggggggg. I HATE FRUIT LABELS.
5. Corn cobs. They don’t decompose very well, and when you pull them out after three years in the compost bin, they are always filled with worms and bugs. UGH.
6. Uncrushed eggshells. I have a superstition about crushed eggshells deterring slugs, so I have been saving my eggshells for this purpose for years. My good friend Dr. Mooks has been concerned that without crushed eggshells, my worms will be unable to digest food properly, so she gives me large containers of eggshell dust to help them. The real reason I don’t like uncrushed eggshells in the compost is because when you pull the half-eggshells out of the bin, they are always filled with masses of worm. UGH.
7. Newspapers. Some people put all their newspapers in the compost. I don’t get it.
8. Cherry pits, plum pits, peach pits. No, these don’t compost either.

That’s it for now…..I am sure I will remember more later.