Worm composting, also known as vermicomposting, is a great way to recycle organic waste at home into a nutrient rich soil amendment/fertilizer known as worm castings or “vermicompost.” This method of composting is ideal for families who primarily generate food scraps rather than yard waste; or, like me, you can have both a worm bin and a compost bin for different purposes. I keep a worm bin in my kitchen, where I put all the leftover pulp from my juicer and other small food scraps like banana peels. Then I have a compost pile in my backyard for more heavy duty garden waste and food scraps. Both methods produce great compost, but worm composting tends to be easier, and can be a great way to get kids involved and interested in compost and reducing waste.
There are various worm bins on the market, but why spend nearly $100 on a worm bin when you can make your own for a few bucks? The worm bin I use at home was made with a couple of plastic storage bins and a drill, and cost less than $10 to make. While it isn’t as impressive looking as a commercial bin, it works just as well!
Here’s how you can make your own worm bin:
- Three 8-10 gallon plastic storage bins and lids (or you can use a smaller size if you prefer).
- It’s best if they are not translucent. (I will call them bin #1, bin #2 and bin #3)
- Drill with ¼-inch and 1/16-inch bits for making drainage and ventilation holes
- Shredded paper or coconut coir
- About a pound of red wiggler worms (They are a special type of worm found at certain nurseries or from local worm farmers)
- Set bin #1 aside.
- Using the 1/16-inch bit, drill about ten ventilation holes near the top edges on each side of bin #2 and bin #3. Keeping the holes small will allow air to flow through without letting fruit flies and other pests in.
- Next, drill about twenty evenly spaced ¼-inch holes in the bottom of bin #2 and bin #3. These holes will provide drainage and allow the worms to crawl into the next bin when the castings are ready to be harvested.
- Now, set bin #2 aside.
- Prepare bedding for the worms, using shredded paper or coconut coir (my preference), a spongy peat moss alternative that you can find at home depot or garden stores. Add water to the paper or coconut coir to create a moist, but not dripping wet, living environment for the worms. The bottom of bin #3 should have about 3-4 inches of moist paper or coconut coir.
- Now add the worms! One pound of red worms will digest about 3-4 pounds of food scraps each week, depending on the material. Red worms multiply quickly and are known to be social creatures, so they don’t mind living in a populous environment. Add a small amount of soil or finely ground eggshells. This provides grit for the worms to help with their digestion.
- Place bin #3 inside bin #1 (the bin without holes drilled). Bin #1 will serve as a catchment bin for the leachate that drips from bin 3. The leachate is also a great soil amendment that can be diluted, and poured or sprayed on plants and soil.
- Now place your bin in a well-ventilated, shaded area and start vermicomposting! Bury food scraps to minimize fruit flies. Place food in different spots every time you add it in order to attract worms to different parts of the bin. Worms will eat most fruit and vegetable scraps, but they like some things more than others. They love coffee grounds, tea bags, and soft items such as melons, berries, and other finely chopped fruit and vegetable scraps. They aren’t too fond of spicy or acidic foods like citrus or onions. Never add dairy products, fats, meat, or oils.
- When bin #3 is full and transformed into finished vermicompost, you can place bin #2 on top of it and repeat step 5 (add bedding). The worms will migrate up to the new bin where there is more food. Then after a month or two, the compost in the bin below will become less populated with worms, and you can harvest the finished compost for use in your garden.
There should be minimal fruit flies and virtually no odors. Building your own worm bin is so simple and affordable, and the finished product will do wonders for your garden. Not only that, but you will help reduce organic waste from going to a landfill, and you can educate your children about their new worm friends, too.