In this blog, we're going to attempt to answer the very basic question, "What is composting?"
Perhaps you are keen on composting because you want to produce rich fertile soil that is best for growing healthy food in.
Perhaps you aim to close the loop in your consumption cycle by going “zero-waste.”
Whatever the case may be, starting with a clear definition and then learning about some easy to advanced composting methods might prove helpful in navigating this simple yet profound act of “returning to the earth” that which has been taken from it.
A Definition: What is Composting?
Composting is the art and science of cultivating the decomposition of organic and more recently, plastic material through biological processes.
The decaying matter is converted by various microorganisms, primarily bacteria, and fungi, into a stabilized soil product that has balanced pH, resists erosion, and has plenty of porosity (holes for oxygen and water). It also contains minerals in a form that can be consumed by plant roots and provides a habitat that supports an abundance of biological life.
It's quite amazing that this miraculous stuff can be produced from dead leaves, grass clippings, and the leftovers of your family’s dinner!
And even more mindblowing is that from this death and decay, comes new life.
The finished product called compost is a result of biological organisms being able to construct microstructures out of proteins and enzymes.
This new soil forms the ecosystem below ground that supports the ecosystem of life above ground.
New Composting Discoveries
Recent studies on the digestive activity of mealworms have revealed that these creatures, (the larvae of the Tenebrio Molitor, a beetle) can biodegrade plastic!
We used to think that the only base upon which we could create compost should always be organic matter. But experiments on mealworms showed that these larvae can digest styrofoam (polystyrene, a type of plastic) and poop biomass!
Therefore, a large part of composting can also involve some bioremediation. This can mean anything from killing off bacteria to cleaning up oil spills!
If you want to go into the specifics of this study, there are bacteria in the mealworms' gut
called Exiguobacterium sp. strain YT2, which creates a film around polystyrene and in about a month or (2) two degrade them.
Other such plastic-eating organisms include the bacteria Ideonella sakaiensis and certain fungi like Fusarium solani. Scientists believe there could be more bacteria in the world responding to the ubiquity of plastics and evolving to digest them.
If dear reader, you know of more research on this, please share your knowledge on the comment space below!
Why we compost
As gardeners in this regenerative age, everything boils down to one thing.
If our soil cannot retain water, provide structure and the life necessary to cycle minerals and nutrients for our plants to uptake. According to this Cornell study, soil is being lost to erosion at a rate of 10–40 times more than it can be replenished… through natural processes.
We can accelerate that replenishment, and grow yummy food to boot, by composting!
Composting also has some added benefits such as:
- increased food production in yields
- the ability to capture carbon by redirecting food wastes away from landfill and reducing the need to purchase store-shipped soils
- allowing us to live a more “zero-waste” lifestyle
- helping us create a cyclical garden system
We can begin to compost right away using what we have. And what we have to start with are the following methods. But first, an overview.
How to Compost (An Overview)
In general, to compost:
- Collect organic material such as kitchen scraps or garden clippings for composting. In the home, you can do this sans the flies, by having a dedicated freezer container and adding to your scrap stash throughout the day.
- Knowing what you have on hand, select and study the composting method that works for you. (See below for specific methods.)
- Find a suitable place in which to place your “active” compost bin or heap. To avoid flies in the home aerobic composting methods are best done outdoors or in a garage. Anaerobic composting such as bokashi can be done right below your kitchen sink. If you are keeping aerobic bins in the home, place a fly trap and some baking soda to absorb odor beside it.
- Maintain your compost according to the method that you’ve chosen by regularly checking on it. Aerobic bins or heaps should ideally be checked daily to a few times a week for signs of rodent infestation and to maintain the oxygenation of the pile. Anaerobic setups should be minimally exposed to air and drained of fermented liquid.
- Test which ingredients to add to create the compost best suited for your type of plants. (See below for which plants need what composting ingredients.)
- Harvest your compost after (2) two weeks to (2) two or more years!
Composting Methods to Try
The following are a few composting methods to choose from. This is by no means an exhaustive list. But here's our list in order of difficulty:
- Indoor Composting
- Ruth Stout Composting Style
- Cold Compost
- Hot Compost
Finally, we also want to tell you why we do not recommend compost tumblers.
1. Indoor Composting
How does one compost indoors? If you do not want to bother with a full-fledged compost pile, yet want to fertilize your indoor plants or nursery seedlings, we have some recommendations.
But first, be warned that this method is a bit hit or miss. Composting involves little helpers in the form of bacteria, fungi, and earthworms. If you try to amend your soil with the following, but your potting soil is dead (i.e no life in it) then the additives such as those we propose below will not be absorbed by your plants.
- Apply coffee grounds to your soil or water your plants with diluted coffee.
- Use pencil shavings especially in pots where your plants are a bit waterlogged and smelly.
- Cut up some fast-decaying banana peels and "work them into" your plant soils.
- Crush up some eggshells. Blend them with some water and water your plants with this high-calcium drink.
- Plant a few peas or beans (from your pantry) into each pot. You're not expecting to harvest the beans. Just hoping the nitrogen-fixing bacteria you introduce in the soil will have a carry-over effect on your plants of interest.
- Put the dust from sweeping your floors into the pots around your house instead of into the trash bin. Just make sure that the swept dust doesn't include any plastic.
2. Ruth Stout's Lazy Composting Style
Ruth Stout was a gardener and author who lived from 1884-1980. Through her work during the era of rising pesticide use, she popularized a very minimalist approach to gardening. Her writing, especially in her book, "Gardening Without Work: For the Aging, the Busy & the Indolent" is a very practical, candid and funny read!
"It is October and I trust that your garden looks terrible, with dead vines, clumsy cabbage roots - refuse - all over it.
And I do hope you will leave everything there, and add the kitchen garbage to it through the winter."
Indeed that is about all she has to say about composting! Ruth Stout did not keep a compost heap but simply stuffed all her scraps into the perennial soft mulch that covered her entire garden.
At the Permaculture Gardens homestead, we use her method for growing potatoes. I think of all popular gardeners, she is perhaps the most deserving of the title, "lazy gardening queen."
Enjoy the video below and watch her in action at 96 years of age!
(Possible indoors, perfect for a deck, garage or in small spaces)
Vermicomposting, according to the Oxford dictionary is "The use of earthworms to convert organic waste into fertilizer."
As good as mealworms are in biodegrading plastic, they are not the first micro-organisms we traditionally turn to when talking about vermicomposting.
The best-known worms for composting food scraps are red wriggler worms or Eisenia fetida.
The few studies we have on the gut bacteria of red wrigglers reveal an rich and diverse microbiology! There are so many different kinds of organisms living inside the red wriggler's gut that 18.7% of them are listed as unclassified bacteria on this taxonomic study of the microbiome of composting worms.
Perhaps you don’t have enough room for the ideal hot composting setup ((2) two composting areas big enough for a 5-ft tall compost pile). Then vermicomposting may work well for you!
Earthworms are amazing creatures that eat organic materials. These worms process and innoculate the material going through their guts, creating vermicasts that are super-charged fertilizer for annual vegetables. They eat up to half their body weight per day. A pound of worms could ideally process a half-pound of kitchen scraps a day into vermicastings.
A Word on the Carbon to Nitrogen (C: N) Ratio
Vermicompost bins are fairly easy to take care of. However, make sure you don’t add too many kitchen scraps (which tend to be nitrogens) in ratio to brown matter (shredded newspaper/cardboard, leaves, etc.). If you notice your worm bin smelling foul, it may be too acidic and anaerobic and environment for your worms to live in.
The ideal Carbon to Nitrogen ratio in most compost piles is 25-30:1.
This means that there are (25) twenty-five - (30) thirty units of carbon for every (1) one part of nitrogen.
But in vermicompost bins, the ideal ratio was determined in this study to be 25.
If this C: N ratio is difficult to fathom, you can find examples of organic material and their C: N ratios in this nifty calculator. You can even combine organic materials to see if the overall pile will have your desired C: N range.
Below is a video in which I demonstrate how I regulate this C: N ratio in a worm bin and consequently, the pH of the compost in it.
How to Make Your Own Worm Bin
You can keep a simple plastic tub for your worm composting which you'll need to turn over with a small trowel or pitchfork every few days.
Below is gardener, Emily Muphy's video on making a simple worm bin. This was how we started before we bought a worm tower.
There are some commercial solutions for worm composting available. The most popular ones are worm towers that involve stacking layers of plastic bins with holes on the bottom for the worms to travel up as they consume the scraps in each layer.
You can collect earthworms from your garden or even build worm trenches or pits directly into your beds.
In our experience, the worm tower is the most hassle-free option.
If you have a productive worm bin you need about a pound of worms (approx. 2000), which you can find at places like Uncle Jim’s Worm Farm.
4 & 5. Cold & Hot Composting
In cold composting, a big pile of leaves or grass clippings sits and rots over several months to several years. This process takes the least amount of work but the results may take too long for our gardening needs.
Enter hot composting or “Berkeley method” composting. This composting process, created at the University of California-Berkeley is managed more carefully. Other composting masters such as Geoff Lawton and Elaine Ingham have further refined this method to create a more complex and complete compost end product.
In a hot composting pile, the C: N ratio you would aim for would be 25-30:1.
If this seems difficult to fathom, permaculture teacher, Matt Powers, and soil scientist Elaine Ingham break it down into 3 piles:
- (1/3) one-third cubic meter of "browns" (dried leaves and clippings that were harvested after they had "gone to seed" in the late summer or early fall
- (1/3) one-third cubic meter of "greens" (green grass clippings or plant materials harvested before they had matured and "gone to seed")
- (1/3) one-third cubic meter of manure.
Hot composting speeds up the cold composting process to an ideal 18-days!
When creating the pile a ratio of 15-20:1 carbon to nitrogen source materials is used. The nitrogen materials provide a high energy fuel created by the reproduction and digestion of mesophilic micro-organisms.
The overall temperature of the pile rises, causing the organic matter to decay much faster. As the pile is turned inside out, oxygen and water help feed the micro-organisms and the temperature further increases.
At this point, thermophilic bacteria take over and further increase the rate of decomposition. As the entire pile nears its final transformation, the temperature drops and the mesophilic bacteria take over again.
What is the Best Composting Bin?
One of the most common questions we get about composting is indeed, "What is the best compost bin?"
The truth is, for hot or cold composting, we do not recommend buying one of the commercial tumbler bins.
We find that during the summer these enclosed plastic bins fry the microbiology that is working to break down are food scraps and waste.
Some bins say that if they are tumbled then you can aerate the bins and make sure they do not overheat. Perhaps this is so in a shady spot or in climates where it is colder during the time that you use the bin the most.
So we propose creating an open bin yourself from pallets like the photo above or enclosing a wooden bin in wire mesh to keep rodents away.
Some folks simply use a round chicken wire or ventilated metal framing as a bin. This definitely helps keep your pile aerobic.
If you have purchased a compost bin and it is working well for your hot or cold compost pile, please share your experience with all of us below!
Perhaps we are wrong.
What differentiates the bokashi method from the most common types of composting is that you deliberately work with anaerobic micro-organisms to “ferment” your kitchen scraps.
You throw your scraps into an air-tight bucket with some of these friendly micro-organisms and ferment the scraps much like you would your sauerkraut.
The result is a thoroughly pickled pre-compost, which you then bury in the garden (but not near your plants) in order to let it finish composting.
Because of this, much of the organic matter which would otherwise kill your composting worms or attract rodents can be placed in a bokashi bin.
Here are some of the things that can be composted using the Bokashi method:
It is good to note, that anything organic can be composted.
An old pair of leather boots.
A dead rat.
Even your humanure.
As Geoff Lawton likes to say, "If it has lived, it can live again."
However, the composting method you choose determines what type of ingredient goes into your bin.
Fungal(Acidic) vs. Bacterial(Alkaline) Soils
One of the interesting facets of composting is that it’s a bit like cooking in the kitchen. You can mix different source materials into your final heap and end up with a different final product.
So it's extremely useful when you are building compost for woody plants to know what kind of soil they like.
The infographic above is a part of a chapter on "Soils" in Matt Powers' book, "The Permaculture Student 2."
In general, trees and bushes will prefer a more dominantly fungal type of compost. You can craft this acidic soil profile by making sure the materials you compost are more woody and carbon-rich. Once again we return to the importance of the C: N ratio. So for woody plants, use a more woody, high in carbon pile.
Your annual vegetables, however, will prefer a slightly alkaline soil made from bacterially-dominated compost.
Recall your elementary and high school science: Acidic means a pH below 7. Basic or alkaline means a pH above 7. Water is exactly 7 and is pH neutral.
Now that you have several composting options to choose from, we hope that you will try your hand at it (or refine your current composting skills)! Please share your efforts: past, present, future in the comment section below. And if you are interested in digging deeper into each one of these techniques above, sign-up for our newsletter (link below as well!).
We know if everyone did their share in eliminating waste, living a simpler life, and returning to the earth, the world would be better for it!