Vermicompost is a powerful, slow-releasing, organic fertilizer full of micronutrients and trace minerals. It is made by worms as they go about their daily lives aerating soil and fertilizing it with their excrement.
Conveniently, it’s also an easy method of composting that can be done indoors in small spaces, all year round!
I made my worm bin and began vermicomposting in my tiny bachelor apartment kitchen about one month ago. Since then, through experience and additional research, I’ve learned a lot about the process. So, I compiled a list of step-by-step instructions that will get you started on vermicomposting in your own space. The results are rewarding: synthetic fertilizer corporations will loathe your thrifty independence and your plants will thank you with growth spurts and blossoms!
Things you’ll need to make:
- Large, opaque storage container. This will be your worm bin (vermicompost bin). The size is up to you! The larger your bin, the more worms you can have and the more compost you’ll get. I used a big ol’ Rubbermaid (61x40x41.9 cm) because it fit perfectly under the island in my kitchen, and I plan on having a lot of plants!
- A plastic tray. This will sit underneath your worm bin. I used a plastic boot mat. Make sure you buy a boot mat that has the tallest walls possible since these will be catching any liquid that seeps out of the bottom of your worm bin.
- A piece of window screen. This will sit inside the bottom of your worm bin to ensure that worms and large debris don’t find their way out of the drainage holes.
- Two pieces of wood. They must be the same height and must also fit inside your plastic tray. Your worm bin will sit on top of them to allow space between the bin and the tray for moisture to drain out.
- Newspaper. (You’ll need lots of it). This will be the cozy bedding for your new pet worms! I make sure to only use black and white newspaper because I’ve read on many websites that colour ink is toxic, and so if you’re growing any edible plants these chemicals can end up in your body later. If the season is right, dead leaves also make great worm bedding. They are a great natural source of carbon. Try mixing both newspaper and leaves!
- A drill. This will be for making air holes in your worm bin. It will make clean, round, even holes. If you don’t have access to a drill, try using a screwdriver or try asking your neighbour. I asked mine :)
- Worms! But not just your typical “lying out on the sidewalk on a rainy day” worms. The only type of worm suitable for your indoor vermicompost bin is called a “red wiggler” (Eisenia foetida). This species appreciates the warm environment and doesn’t have any qualms with living in its own feces. You can order red wigglers online or buy them at some bait shops, garden centres and worm farms. But first, try saving some money by asking around for someone who may have an excess of them (they can procreate quite rapidly). Or, try working for them. I got my worms at a local community greenhouse for just 2 hours of volunteer work!
Method for constructing the worm bin:
1. Drill some 1/4 inch holes into the bottom of your worm bin. These will allow excess moisture to drain out so you don’t end up with worm stew. The number of holes is up to you, but don’t put too many or you’ll risk a weak bottom. I put 6 in mine.
2. Drill some more 1/4 inches holes into the sides of your worm bin. These are the air holes. Again, the number is your choice, but I suggest you give the little guys at least 20 of them. I put a total of 26 along the sides of my bin.
3. Line the inside bottom of your worm bin with the piece of window screen. I used some leftover pieces of screen to cover the air holes from the outside as well. It is a completely unnecessary step, but if you’re a bit obsessive and enjoy being prepared for unlikely scenarios (in this case: the worms escaping from the air holes), then you can do this too. I simply stuck the screen to the outside of the bin using hot glue around each hole.
4. Put the lid on and stand your worm bin on top of the two pieces of wood placed inside the plastic tray. Voila! A miniature ecosystem awaits.
Now it’s time to make the bed…
How to prepare a bed for your worms:
1. Shred your newspaper into strips and small pieces. This task is kind of tedious so if you possess a paper shredder then you’re in luck! If you are using dead leaves, try to crunch them up as best you can; for example you could put them in a plastic bag and break them up with your hands or run over them with a car.
2. Pre-soak your shredded newspaper. Put it in a bucket, add water, and let stand for a half an hour or so.
3. Make the bed! One handful at a time, squeeze out excess water from the soaking newspaper and distribute it in the bottom of your worm bin. The newspaper should be damp, but not dripping water before it goes in. You don’t want to risk drowning the poor worms! Also try to “fluff” up the newspaper by ripping it some more to separate the pieces. If you find that it’s taking you a long time and the newspaper starts drying, moisten it with water in a squirt bottle. Fill your worm bin about halfway with bedding.
Now you’re ready to make poo!
Method for making poo (other than the one you already know):
1. Release your worms in their cozy new home. Make sure you locate their home in an area that will not get too hot or too cold. They may not survive temperatures lower than 50 degrees F and higher than 84 degrees F. Also ensure that their home will not be susceptible to drying out completely (direct sun all day) or to flooding (heavy rain).
2. Feed them your food scraps! Keep in mind that the smaller the food scraps, the faster your little workers will be able to transform them into brown gold. Put them through a blender first, or chop them up into smaller pieces. Also, try not to overfeed them. Too much food scraps in your worm bin will start to smell and attract unwanted insects and bacteria. I’ve read that they eat their body weight in food each day, so 1 lb of worms can consume about 1 lb of food in 24 hours. I suggest giving them a small amount at first and monitor how long it takes them to get through it in the following few days. Use your best judgement and only add more food scraps when you feel they can get through them in a reasonable time frame.
What to feed your worms:
- Fruit and vegetable scraps; cores and peels.
- Coffee grounds (not too much) and tea (remove staple from the bag).
- Eggshells (crushed)
- Grass clippings
- More newspaper
- Dry grass
- Hay and straw
- Dead leaves
- Paper egg cartons
How to harvest your vermicompost:
Depending on how many worms you have and how much bedding and food you’ve provided them, you may have a crop of usable fertilizer in just a few weeks or after a few months. When your worm bin contains lots of rich, dark brown sludge with few visible newspaper and food pieces, it’s probably harvest time.
1. Scoop all of the vermicompost over to one side of the worm bin.
2. Add new bedding and food scraps to the empty side.
3. Have patience. Wait a week or two. Your worms will make their way over to their new bed leaving behind all their hard work to your benefit.
4. Scoop the vermicompost out and make good use of it. Spread the new bedding around and start all over again.
What to do with your vermicompost:
- Sprinkle them on the surface of the soil around your plants and give them a good watering. The nutrients will seep down to the roots where they are needed, and the layer will act as mulch helping to keep the soil moist.
- Blend vermicompost into regular potting soil. Try mixing 30% vermicompost with 70% potting soil.
- Make worm poo tea. Steep some vermicompost (in a tea bag or in the foot of an old pair of pantyhose) in tepid water for about 24 hours. Dilute to 1 part poo tea and 1 part water and treat your plants to a drink of the nutritional brew. Similarly, you can dilute any liquid that seeps out of your worm bin’s drainage holes and give your plants a sip.
- Store them for later use. Make sure to store your vermicompost in a non-airtight container, such as a brown paper bag. It will keep for well over a year in this manner. (If you store it in an airtight container, you will be risking mold and other harmful bacteria growing in there as the organic matter continues to break down in storage).