A Beginner’s Guide to Compost

What is Compost?

We’ve all heard of it, maybe even garden with it regularly, but could you define it?

Compost is essentially organic material that has been converted by microbes to a state that makes the nutrients readily available for plants to take up again. In addition to food scraps and yard trimmings, there are many other sources of organic material readily available including your composting toilet contents!

Want to hear what the experts have to say? 

US Composting Council: What is Compost?
Humanure Handbook: Compost Misunderstood Chapter

Open Air Composting

A pile, a heap, a mound. It’s organic matter, a balance of carbon and nitrogen-rich material, sitting on the ground or contained in an enclosure that is open to the air. This is the most commonly used method of compost. The heat generated by the microbes doing their thing means that it works relatively quickly so that animals are less likely to be attracted. You can even bury water lines in the compost to harvest the heat for hot water! 

Doesn’t it stink? If rotting food in my fridge stinks then a pile of it in my yard must be pretty rank, right? Yes, just putting a pile of food in your yard would be disgusting and attract animals and flies. Adding human excrement to this would be even worse. However, by covering the pile with carbon-rich material such as hay or leaves and mixing in plenty of this matter, you get rid of the smell entirely AND allow the compost pile to get hot so it breaks down even faster. Human excrement is nitrogen-rich while sawdust, peat moss, coco coir, and other toilet cover materials are carbon-rich, so your toilet contents will already be in perfect balance when added to your compost pile.

Underground Composting

This one is exactly what it sounds like: you bury the organic matter underground. The cons to this particular method tend to outweigh the pros of having an invisible compost spot. It takes much longer for the contents to compost when they are buried and you risk having animals dig it up as it smells like something edible for a lot longer than with the hotter, open-air compost. Don’t forget to add plenty of carbon-rich material to feed those microbes. Also, you need to have the space to dig a whole bunch of holes over the years!

Tumbler

Social media for composting? Alas, no. This is another type of tumbler. Many people in urban areas and neighborhoods like the “out of sight” appeal of tumblers. They are typically some sort of barrel mounted sideways on a pole that allows you to turn the compost over, thoroughly mixing the carbon-rich and nitrogen-rich material. This mixing can speed up the composting process but, as the bin fills up, you need to be fairly strong to turn it daily or at least every couple of days.

Compost Share/Donation

Maybe you don’t have the space, the interest, or the long-term commitment to one location to produce your own compost, but you still want to reduce your contribution to the landfill and get those nutrients back in the soil. Chances are you can find someone who will be positively giddy to take your organic material! Check-in with friends or local community gardens. There is even a website, ShareWaste, where you can look for folks accepting compost material near you. Keep in mind, many places won’t be willing to take humanure. Tip: be a buddy and bring your compost contribution complete with plenty of carbon-rich material already added in.

Worms

Worm bins are another way to turn food scraps into plant-ready nutrients but its actually a completely different process and gives you a different product than compost. Worms do not compost; they eat and poop, and in their droppings, called castings, are tons of great nutrients for plants. However, this is not, by definition, compost. Worms may or may not be present in a compost pile but it’s the microbes doing the composting process. 

A highly debated topic but a simple rule is that if it will rot, you can compost it. So the question is, why is there so much information out there about what not to compost? From our research, it seems that there are a few reasons why you might choose not to compost certain items. 

1. Some organic matter takes longer than others to fully compost. If your main focus is getting compost as quickly as possible, you may want to avoid adding avocados, peach pits, corn cobs, or wood that is not chipped smaller than sawdust size.
2. Animal products (meat, dairy) are the most likely items to produce smells or attract other animals to the pile. If you are not yet confident in your ability to eliminate smell with the proper quantity of carbon material, you might start composting without these items and add them to your compost in the future when you feel ready.
3. Chemicals are in so many man-made products and you may not want these present in your garden. Things like most colored ink (paper that’s been printed on in color), cleaning supplies, herbicides, and pesticides don’t belong in your compost.

How to know when it’s ready

Many factors go into how quickly or slowly a compost pile will take to fully mature, including the weather and size of material. Generally, it should be ready about a year after you stop adding to it. If the pile isn’t getting very hot, and you have been adding your toilet contents, wait another year so you can confidently use your compost. Inspect your compost and smell it. Finished compost should have a nice earthy scent.

Using compost

The main reason humans make compost is for gardening. It is a soil amendment packed full of natural nutrients ready for plant use. It holds more moisture than any type of soil so you can go longer without watering during a dry spell. You can mix it in with your garden soil, add it around bushes and flower beds, and plant seeds directly in it. You can’t go wrong growing plants with compost.

Resources

The Humanure Handbook by Joseph Jenkins – read free online or order printed book

US Composting Council

Nrdc.org

ShareWaste