In an earlier article we talked about different methods for traditional composting yard and kitchen waste. Today, we’re going to cover Vermicomposting- composting with worms! Composting, the process of taking raw organic material like kitchen scraps, lawn trimmings, dead leaves, and chipped woody material and turning it into a useable, stable, non-offensive soil amendment can be done in any living situation. By composting our green waste and kitchen scraps, we reduce our impact on landfills and enrich the soil in our yard and gardens. For this discussion, we’ll be using the word “organic” to mean anything that is alive or was once alive like plants and animals or any waste produced by plants and animals. Organic material accounts for as much as 52% of the garbage humans create. That’s a huge amount of material ending up in our landfills that could be utilized in our yards, gardens, and even our planter boxes.
Vermicomposting Is An Efficient Way To Reduce Trash
Vermicomposting, also known as vermicasting, is the process of using worms to break down those materials and turn them into a rich, dark, humus-like substance that can be added directly to our gardens without aging it. Like traditional composting, vermicomposting breaks down organic material, but is much easier to do on a smaller scale and is an excellent choice to compost kitchen scraps in a controlled, enclosed, odorless environment. It’s clean, socially acceptable, requires no physical effort on your part to keep aerated (traditional compost must be turned), reduces the mass of waste by 30% or so, and even creates more worms that can be used for fishing. It’s also faster than traditional composting. Vermicomposting takes about 22 to 32 days to turn organic waste into castes (worm poop) whereas traditional composting can take 30 to 40 days for hot composting or even years for passive composting.
Although food waste can be added to traditional compost piles, adding kitchen scraps to compost piles comprised of dead leaves and other yard debris can also attract unwanted pests like rats and raccoons. Rats especially love compost piles- they like to burrow into the warm pile and enjoy feasting on all the kitchen scraps you’ve provided. Left unchecked, they breed very quickly and can spread disease. They’ll also eat eggs from your coop and kill your poultry. We were recently reminded of how destructive rats can be when they got into our quail coop.
We raise our quail on the ground on a coop tall enough for them to fly. We prefer this method as it allows the quail to behave naturally and build up their muscles, thus giving the meat a texture closer to wild quail. We use a gravity flow water system that feeds into multiple automatic watering cups. We had drilled small holes in the side of the coop to thread the water hoses through, but when one recently busted, we pulled it out and meant to get back to repairing that one cup when we had more time. We soon noticed our quail had stopped laying…or so we thought! Young rats can fit through an opening the size of a quarter! They were feasting on the quail food, gorging on eggs, and enjoying the fresh, clean water provided daily. Within a very short time, we had a multi-generational rat infestation. I can tell you from experience it’s much easier to take steps to prevent the rats from wanting to set up house than it is to get rid of all of them once they do.
Vermicomposting solves this by using worms to compost kitchen waste in a controlled, closed environment. In order to get started, you’ll need:
- A container
- Electric drill
- Bedding (shredded cardboard or paper, dry leaves, wood shavings, or straw)
- Red worms (Eisenia fetida)
- kitchen scraps
Many urban gardeners use vermicomposters as a way to get started with raising worms. You can buy a worm bin like the Worm Factory or simply build your own. Arguably the easiest way to build your own is to purchase a plastic storage bin with a lid. The size of the tub will depend on the amount of food scraps you think you’ll generate in a day. Generally, worms can eat about 75% of their body weight in food scraps in a day, and the bin should have one square foot of bin surface area for every half-pound of food scraps. Use the formula of width in inches divided by 12 times length in inches divided by 12 (or W/12xL/12). A tub similar to this one would work well. Avoid clear or see-through tubs. Worms don’t have eyes, but they do have light sensors on the surface of their skin. Light causes them pain and they’ll run away from it. It’s better to use a bin that is opaque.
Building a DIY Worm Bin
The best type of earthworms to get for composing are Red Wigglers. These are heavy feeders and have been shown to thrive in worm bins. Like every other living thing, worms need three basic things for life: food, water, and air. You’ll need to drill some holes in the bottom and sides of the tub to allow for air circulation and for water to seep out. The number of holes you’ll need depends on your climate and how moist the food is going into the tub. It’s better to err on the side of caution and drill too many holes than it is to not drill enough. If you’re concerned about castings falling out of the bottom of the tub, use a liner. An inexpensive nylon sheer curtain works well.
If you’re going to use the lid of the tub as a catch basin under the tub, don’t drill holes in it. Place it upside down under the tub and fashion a new lid for your worms (remember, they like it dark!) our of a piece of cardboard or plywood cut to the same size as the tub so that it rests on the lip of the tub or even overlaps a little. Avoid having the cardboard or plywood lid so small that it fits into the tub and will be resting on the bedding and worms. Not only does this cut off some of the airflow to the surface of the material, but your worms will happily compost your lid right along with your food scraps.
Here’s a great video to follow step-by-step:
Bedding Material and Moisture Level
Once you have the holes drilled in the bottom and sides of the tub and the plastic lid flipped over and under the tub, it’s time to get your bedding material ready. No matter what you choose – shredded paper, sawdust, straw, etc- it should be soaked in water. Allow it to sit in water until it has soaked through and then drain it. You might need to squeeze the water out. The goal is to have your bedding about as damp as a well-wrung sponge. Any water and the worms might drown. Too dry and they’ll die from lack of water absorbed through their skin. The ideal moisture level is about 75%. Place handfuls of bedding in the bottom of the bin and fluff the bedding up a little. Fluffing allows the bedding to develop little pockets of air so the worms can get enough oxygen, too. If the bedding is too compacted, the worms will have a difficult time burrowing through it and may trap too much moisture. It could also create an anaerobic (lack of oxygen) environment which encourages rot and foul odors. Keep your bedding layer to 1 foot deep or less to prevent compaction.
Worms can survive temperatures ranging from around freezing to as high as 100 degrees Fahrenheit, but their productivity will suffer at either of those extremes. If you plan on keeping your worm tub in an area protected from temperature fluctuations, like a garage, basement, or mudroom, there’s no need to insulate the tub.
Adding Your Worms and Feeding Them
Now it’s time to add your worms. Place about a half pound to one pound of worms for every square foot of surface area in your tub. Red Worms are epigeic, meaning they’re surface dwellers. More accurately, they live just under the surface of the soil, whereas other types of worms (like night crawlers) can tunnel much deeper. Place your lid on the tub and allow the worms to settle down into the bedding for a few hours before feeding them. It’s a good idea at this point to keep a bright light on over the lid. This encourages the worms to burrow down into the bedding instead of trying to crawl out and away from the tub. After about a week, the light can be removed.
Once the worms have settled into their new habitat, it’s time to feed them. Worms will eat just about any organic matter, but you’ll get better and faster composting if you chop it in into small pieces first. You should also avoid adding high acid or salty kitchen scraps like citrus. Meat, bones, dairy products, greasy foods should also be avoided. The worms won’t eat them and it encourages other pathogens to populate your worm bin. Of course, never, ever add dog, cat, or bird poo or any feces of a meat-eating animal. It’s better to feed once or twice a week than it is to disturb the bin daily to add more scraps. To feed, simply pick a new spot each time, create a small hole in the bedding, and drop the scraps in. The worms will migrate over and find the new feeding spot.
When the conditions are right, your worms will start reproducing. Worms are hermaphroditic, meaning they have both male and female organs. The thick band near their head is part of their reproductive system. Each worm can produce an egg capsule (cocoon) every seven to ten days. In fourteen to twenty-one days, two to four baby worms will emerge. Baby worms will mature to breeding age in about two to three months and the adult worms can live as long as seven to ten years.
Maintaining a worm bin is relatively simple once the worms have been provided the right amounts of bedding, air, moisture, and food. Fresh fruits and veggies are about 90% water, so there’s usually little need to add more moisture to the worm bin once you’ve soaked the initial bedding. Over-feeding can be an issue and will cause odor and attract flies, so carefully measure the amount of food you’re giving your worms until you get a feel for it. If, after the first week, you see worms trying to escape, there is something wrong in your worm bin- check their basic requirements again for water, air, and food to make sure they’re in the right balance. Stay tuned!