Today we are talking about vermicomposting; using worms to break down food-waste into soil. There are already some excellent resources online about how to get set up for vermicomposting. Today I just wanted to talk about our reasons and experience at The Thinking Forest. Everything I'm going to talk about is my little DIY experiment. You might save yourself a lot of trouble by investing in a vermicomposting bin. They usually have different levels built-in so you can easily separate the worms from the compost.
Why did we do it?
- It is less expensive than food-waste bags/trash.
- I'm not sure what the city is doing with food waste. It may just be going to landfill (in plastic) or burning (in plastic). I doubt it's being reused or broken-down properly.
- Compost! Free, fertile soil for the plants we will be planting.
- Interesting. Just seeing the worms do their thing (or not) is a pretty exciting experience.
How did we start vermicomposting?
- A bucket - consider how much food-waste you have per month. You need a bucket that can hold at least that.
- Some cardboard/paper/ or brown leaves and grass cuttings.
- A bit of water
- A bit of dirt
We drilled a few holes about 5cm from the bottom of the bucket for aeration. I'm not sure if this was necessary. It also allows the worms to escape if conditions are not perfect.
Next, we put cardboard in the bottom of the bucket up to the holes. We added just enough water to get the cardboard damp. No water was standing on the bottom of the bucket. Next, we put a layer of dirt from the garden on top of the cardboard. Don't compress the soil. Keep it light and fluffy. We added a little bit of water to the dirt because it was dry.
After that, we threw in some food-waste scraps that were crushed as small as we could quickly get it. We mixed the food-waste scraps with the dirt, then added the worms.
We started vermicomposting about one month ago. I dug a hole in the garden and found about five worms that I threw into a bucket. The bucket was leftover from The Thinking Forest renovation. Cardboard is abundant. So, overall, our initial cost was almost nothing.
With only five worms the food-waste composted a little slower than then amount we wanted to add per week. We found another 40 worms or so, and the process sped up to more than what we put in. Every time I added new food-waste, the prior waste was mostly finished. I would add additional cardboard and paper when it looked too wet in the bucket. The bucket stayed in the shade, and I never saw it dry.
While vermicomposting was visibly working, there was no smell. I kept a lid on the bucket, and sometimes flies would get in, but removing the cover did not hit you with any significant smells.
The amount of food-waste the worms have broken down would probably be equal to several food-waste bags. Just in a month, the costs have been recouped. A professional system would probably be more efficient and more comfortable to remove worms from the compost. Even professional systems could probably break even after a while. I'll be doing calculations about it later.
A closed vermicomposting system could probably be run in a house quite efficiently. With little maintenance, there would not be any smell.
When things go wrong, you know pretty quickly. The weather last week was hot, humid and lots and lots of rain. When I went to add more food waste, the older waste was not as processed as I expected, and I started to smell a mighty stink.
The compost in the bucket was very moist. Adding additional cardboard would not be enough, so I put it in the hot sun to try out a little. Some moisture was removed, but not much. We then mixed the compost a bit, and only found one worm. The others seem to have escaped… meaning that the environment was not good for them.
While the compost system was working, it was terrific. When it stopped, it takes some effort to get it going again. Specifically,
- Making sure the moisture levels are fixed
- Getting more worms
Before we started vermicomposting, some people recommended drilling holes in the bucket and burying the bucket in the garden. I didn't understand at the time, but this would give you access to covered compost, and the worms can come and go as they want. Now it makes sense to me, but I'm not sure if it will here. The video below describes what we are trying to do by burying the bucket.
There are quite a few resources available online about vermicomposting. As long as you can control the moisture levels in your bin, everything else is pretty hands-off. Get some great compost and save some money while not doing much. Sounds good to me!
Before we started, we looked at a lot of resources. Below are a few that should help to get you started.