Can You Compost That?

You can turn almost any organic material into rich, nutrient filled compost, but some things take longer than others. Here’s what to know and how to do it

You can compost a surprising number of things

A compost pile isn’t a thing, it’s an entire world of things.

Billions of organisms – microbes, fungi, worms, insects, and more – all feeding, growing, reproducing and dying while turning kitchen, household, and garden waste into rich, organic fertilizer and soil amendments.

In nature, decomposition of plant and animal materials happens continuously but gradually over a period of months or years. Making a compost pile speeds that process and, depending on the type of composting you’re doing, can shrink the process down to a few weeks.

Here at The Acre, we compost nearly everything that can be – spent vegetables, plant trimmings, leaves, weeds, old straw, chicken and duck manure, even paper (plastic free) and cardboard. All totaled, it’s around 75% of the stuff we might otherwise send to the landfill.

Most of the materials we compost wind up in one of the two big compost piles down in a corner of the yard. Those are “cold” compost piles which work gradually, breaking down materials in three to six months. But some of it – mostly small stuff like kitchen scraps and household paper wastes – goes into the compost bin in the center of the keyhole garden. The high amount of fresh, green matter in that bin makes it a “hot” compost pile that’ll turn materials into black gold in a few weeks. It’s so full of activity you can often see it steaming on chilly mornings.

Making a Compost Pile

The point of building a compost pile is to create an environment where composting organisms can grow and thrive. These critters have four simple needs: food, water, air and insulation from the elements. Some seem to think that in order to kick off composting activity they need to add a compost starter or otherwise introduce organisms into the pile, but the truth is, if you build your pile right, compost critters will show up all on their own. All you need to do is understand a few basic composting principles and Mother Nature will take care of the rest for you.

Compost Components

Pretty much anything of living origin can be composted. It’s the quality and proportions of the materials you use that will determine speed and nutrient density of the finished compost. The organisms that do the actual composting need the right proportions of two elements: nitrogen and carbon. Nitrogen is necessary to form proteins which allow the organisms to grow, and carbon provides the energy to do it. But, if there’s too much nitrogen it will leech out into the air or water before it can be used. Too much carbon and decomposition will slow and you’ll end up with nitrogen-depleted results.

Experts say the ideal proportions of carbon to nitrogen (the “C/N ratio”) is 25:1 or 25 parts carbon to one part nitrogen. But since it’s not very realistic for the average person to be measuring the C/N ratio of everything they toss in to compost, a simpler rule of thumb is 2 parts ‘brown’ and 1 part ‘green.’

• ‘Brown’ materials (high carbon) = dry brown things like corn cobs, dried stalks, straw, hay, pine needles, paper, cardboard, sawdust, etc.
• ‘Green’ materials (high nitrogen) = fresh, wet things like grass clippings, fresh plant cuttings, green leaves, fruits and vegetables, etc.

(There is a more extensive list of things you can put in your compost pile below.)

You don’t have to be exact about your proportions of brown to green either (I’m not). Just make sure you’re not overloading your compost with too much of one type. If your compost pile starts to look dry and crunchy, layer on some green stuff. If it starts to look wet and sloppy, mix in some brown. It’ll find its balance and be just fine.

One other thing to remember is the wider variety of stuff that goes into your compost pile, the more likely it will thrive. And a thriving compost pile is a good compost pile.

You know it’s good compost when it’s full of worms

What things are compostable

As I mentioned earlier, everything of organic (living) origin is compostable, though some things breakdown more quickly than others. A lot of the things that people think aren’t compostable is because they think if it’s unhealthy or inedible for people and pets, it’s not compostable.

For example, I’m asked all the time: “can you compost orange peels?” The answer is, “Yes, of course you can!”

Presumably people are cautious about tossing citrus peels in the compost because they’re acidic. However, in a compost pile, just like in your digestive tract, there are numerous microbes and critters who have no problem breaking apart those acids, converting them back into their base compounds (mostly carbon, hydrogen, and oxygen) to make them available for other organisms.

The same goes for all kinds of things that people might otherwise be hesitant to toss into the compost including greasy, oily, salty, spicy, fatty, and woody things. If it’s of organic origin, it can be composted.

The one exception to this is plastics and synthetic oils (e.g. motor oil). While they are technically organic in origin, their molecular makeup makes them extremely difficult and very slow to convert back into simple molecules using natural methods.

Here is a quick list of things you can toss in your compost pile: