How to Vermicompost

The Contribution of Your Kitchen Scraps to Global Warming

Not all food waste is avoidable. Coffee grounds, banana peels, onion and potato skins, eggshells, and the plate of spaghetti your toddler dropped onto the ground all contribute to the kitchen waste a family produces. Millions of households in the United States, however, simply throw those kitchen scraps into the same garbage bin where plastics, glass, and other household trash end up.

By not separating organic waste, like your kitchen scraps, from other sources of household waste, all trash ends up in the same landfill. Because of the sheer amount of incoming waste sent to landfills around the country, organic waste products decompose anaerobically (without access to oxygen), and this leads to the production of methane, which is one of the most dangerous and potent greenhouse gasses.

The EPA estimates that methane makes up 50% of the gas emissions from landfills and that municipal solid waste is responsible for over 15% of all methane emissions in the country. Because methane is 28 to 36 times more effective at trapping heat in our atmosphere, those banana peels that end up in your kitchen garbage bin are directly contributing to global warming.

What is Vermicomposting?

Often with household scraps, we consider composting. What if there was another option, one in the comfort of your own home? Vermicomposting could be a great option to add to your household all year round - and here's why. 

Vermicomposting is the breakdown of organic materials through worm digestion. As the worms move through your compost pile, they consume the waste and store it in their crop before moving it past into the gizzard (like in birds).  

Here the material is broken down by small rocks that the worm has swallowed and passes through the simple intestine. The remaining worm excrement, or worm castings, are full of non-digested nutrients and coated in beneficial microorganisms that line the worm's digestive tract. When castings are left to sit, through the aid of soil microorganisms, they begin to breakdown further into a humus-like substance.

Vermicomposting is comparable to standard composting with a few differences. First, vermicompost is a cold composting technique. The high temperatures regular compost reaches are not achieved here, which could result in the potential germination of seeds in your compost. Second, the process requires less work because the worms turn the material for you, so you don't need to get your hands dirty. Finally, this can be done inside and odor-free with the right balance of compost materials and design.

How Do I Start Vermicomposting?

You can find various vermicomposting strategies online from a small apartment to a large property system. I discovered that Soni Cochran listed it best with five simple requirements: a container, some bedding, water, worms, and food scraps.

Vermicomposting Bedding

The bedding is comprised of shredded materials like cardboard or newspaper and will make up roughly two-thirds of your container. The size of your bin will ultimately determine the amount of shredded material you will need. Ame Vanorio recommends approximately two to four pounds of bedding per 2-foot square container.

There are a few things to consider if you're choosing to add manure to your vermicompost bin. First, be sure to use manure from herbivorous animals. Popular choices for a home would be guinea pigs and rabbits, but you can also consider manure from horses, goats, and even chickens. Next, ensure to add dry manure. Wet manures are too "hot," meaning that they will cook the worms. Do not include dog or cat feces as these can contain pathogens in them.

You're going to want to ensure that the materials are thoroughly shredded, to give the worms the ability to move freely through it. The bedding acts as a substitute for a natural litter of leaves, manures, and well-decomposed woody debris. Aim to try and mimic natural soil conditions as best you can, meaning airy and moist.

Vermicomposting and Water

When dampening your bedding, there is a line between too wet and too dry. Aim to have your bedding the consistency of a well-wrung sponge or washcloth. If you firmly squeeze the material, if adequately saturated, moisture will begin to appear at the edges but not drip off.

You can leave two inches of water in the base of your bin and allow it to be soaked up by the bedding. Or you can dampen the materials as needed when it begins to dry. Be sure to pour out excess moisture, as too much can also negatively affect the worms.

When it comes to dampening your vermicompost bedding, don't be afraid of trial and error. Making sure you've got the right moisture level is ideal in successful vermicompost.

Vermicomposting Worms

Now for the linchpin of vermicomposting: the worms. The worms you want to use in your system are Eisenia fetida (red wiggler). This shallow soil species lives in the top few inches of the soil and prefers temperatures between 55-77°F (12-25°C). When exposed to temperatures below freezing or above 84°F (29°C), the worms will die, so be sure to bring them in during the cold winter months and away from direct sunlight.

These little worms have a respectable processing rate of 2:1, meaning that one pound of worms can process half a pound of food daily. And with ample food, this species will reproduce well in captivity.

Other worm species do not do as well in vermicomposting, with some preferring the ability to burrow deep into the earth. But you don't have to dig up the garden to find red wigglers. There are plenty of places that you can purchase the worms online or from your local garden supply store.

Where Can I Buy Vermicomposting Kits and Supplies?

Because of the increasing popularity of kitchen vermicomposting, several online companies offer "starter kits." These kits often contain red wrigglers, other types of composting worms, and other vermicomposting supplies. This company sells red worms, by the pound. Others sell starter indoor composting bins and additional accessories.

Benefits of Vermicomposting

Having a bin of worms underneath your sink might not, at first, appeal to the everyday homeowner. However, when properly managed, this bin will emit absolutely no smell. The worms will quickly and efficiently turn your kitchen waste into fertile topsoil that you can then "harvest" for the benefit of your household plants or small vegetable garden.