What is composting? Composting is a process in which organic materials such as food scraps, paper, and leaves are broken down quickly thanks to optimal conditions for decomposers. Decomposers are tiny organisms – both seen and unseen – that break down dead or decaying material for their own life needs. This process makes nutrients available in the soil for plant growth: an amazing regenerative system that keeps life going and growing.

 

How does composting work? Composting works in three stages. We’ll use an apple core as our example. Note: Even though visible decomposers like earthworms and roly-polies do their part, we’ll focus on the activity of microscopic organisms. 

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Step 1: Mix an apple core into your compost pile. Soon, mesophilic microorganisms – microorganisms that live in temperatures of 68 to 113 degrees Fahrenheit – will begin to break it down. 

Step 2: Just a few days later, thermophilic microorganisms – microbes that live in very high temperatures – will begin to decompose your apple core. This stage can last from days to months. During this stage, the metabolic activity of these microbes will make some compost piles so hot that the temperature can kill the microbes off. To prevent this tragedy, you may want to turn your compost every couple of weeks. Turning the compost also introduces more oxygen into your pile, which is of great benefit to the decomposers.

Step 3: Thermophilic microbes have finished getting what they need from the organic material, and step back, so to speak. The compost pile begins to cool down, enabling the mesophilic microorganisms to have one more swing at it. This finishing process takes several months. 

 

What makes a successful compost system? There are 4 main components that lead to a successful compost system: air, “browns,” “greens,” and moisture. Let’s break these down (no pun intended):

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1. Your compost pile should have adequate access to oxygen, which keeps decomposers alive and thriving.

2. Browns are sources of carbon such as branches, twigs, shredded paper, and dead leaves. This carbon gives decomposers energy for living. 

3. Greens are sources of nitrogen such as fruit scraps, grass clippings, and vegetable waste.  The nitrogen helps decomposers function. 

4. Depending on your compost system and the material you typically add to it, you might need to add a bit of water to your compost. You want it to be moist, like a wrung out sponge, but not soggy.

 

Basically, these elements create a healthy home for your decomposers. If they’re thriving, they’re decomposing the compost material at a good rate. If they lack something they need, they’ll slow down. You can often tell what your decomposers need by the state of your compost. 

• If it’s slimy, add more browns. 

• If it’s dry, add more greens. 

 

For best results, consider “lasagna-style” compost by covering each layer of “greens” with a layer of “browns.”

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Do I need earthworms? Although worms are helpful in turning waste into “black gold,” they are not necessary. There are plenty of invisible micro-organisms also doing this work.  

 

What kinds of decomposers other than bacteria might I see (or want) in my composter? Some decomposers you might see in your compost are earthworms, beetles, sow bugs (roly-polies), millipedes, earwigs, and springtails. You might also notice helpful fungus including mushrooms, but the bacteria will be invisible. Compost piles also attract predators of decomposers, such as the centipede.

What are some other methods of backyard or household composting? 

Your Earth Machine is a slow yet reliable composter, and it’s a great way to start your composting journey. Here are other methods you could try in the future:

• Open air composting simply consists of an open pile of “greens” and “browns” in your backyard.

• Direct composting is burying your scraps into holes or trenches in the ground. This method generally takes a long time to decompose organic matter.

• Tumbler composting utilizes a container that you can rotate to turn and mix your compost, expediting the process.

• Worm farms (vermi-composting) uses a container with soil, food scraps, and worms. It’s a good year-round project for basement composting.
   

Click here for more info on different composting methods.

 

What shouldn’t I put in my compost – and why? 

• Black walnut tree leaves or twigs may release chemicals that could harm plants

• Diseased or insect-ridden plants may contaminate other plants

• Chemically treated yard trimmings could kill organisms that help break down material in your compost

• Pet wastes may contain harmful pathogens

• Dairy products may attract pests

• Fats, grease, lard, or oils may attract pests

• Bones and scraps from meat may attract pests

 

Click here for more information on what you should not add to your compost and why.

 

What other composting tips do you have? Consult your easy-to-read Earth Machine manual. Other useful websites include:

• Composting At Home – The EPA

• 7 Secrets to Perfect Compost – The Modern Farmer

• How To Use Your Earth Machine – County of Santa Cruz Home Composting Program

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We consulted the following resources in building this FAQ:

 

“Composting At Home.” EPA United States Environmental Protection Agency, EPA, 15 July 2020, www.epa.gov/recycle/composting-home. 

 

“Decomposers.” National Geographic Society. 17 Dec. 2019, www.nationalgeographic.org/encyclopedia/decomposers/

 

Ross, Rachel. “The Science Behind Composting.” Live Science, Future US, 12 Sept. 2018, www.livescience.com/63559-composting.html