Our story with compost worms started a while ago, in 2008, when we met worms of Eisenia Foetida family during a gardening festival in Parc de Bercy at Paris. It was a perfect opportunity to start a mini vermicompost bin in our apartment. After only a few time, our worms were producing a high quality compost and liquid fertilizer that our small balcony garden appreciated very much. During these years, traveling with our worms, we learned a lot on vermicomposting that we would like to share in this brief post, and in a more extensive wiki guide for everybody : vermicomposter.wikispaces.com
Why is vermicomposting important?
Composting worms are one of most important actors of soil health. They transform food scraps and organic material into a rich fertilizer, making gold out of waste ! They produce vermicompost, a nutrient rich fertilizer and soil conditioner that improve soil moisture retention, eight time more powerful than classic compost. In our consumer society, vermicomposting is a healthy way of returning to nature a part of what we take from it and create life from compost rather than disaster from chemical fertilizers.
How to build your own worm bin ?
Since we vermicompost, we built a series of compost bin, adapting the design to different situations and conditions. An easy to build small compost is sufficient to create a healthy environment for your worms.
A simple design consist of two, three or four boxes are simply piled into a composting tower. The box at the bottom serves to collect the liquid, while the other boxes are filled, one at the time, with worms and scraps. The principle of this vertical design is that worms consume the scraps and then migrate up to the next box with fresh food, while water enriched by percolating through the compost collects at the bottom. Then mature compost and liquid fertilizer is easy to collect and emptied boxes can be piled on the top and filled with food again. You can simply take similar plastic boxes, pile them and drill holes at the bottom of all boxes except the one at the bottom. Air holes can be drilled at the sides to allow breathing. The compost bin must be designed to balance sufficient breathing with high humidity, which may depend on your local conditions.
We made such bins using different materials. We built small versions with plastic bottles cut in the middle and covered with a tissue (see the photo). We also made larger ones with polystyrene boxes of the same size. We also built a mobile one with two 20 cm food plastic containers, that can be easily closed and packed, and that holds enough worms and compost for a small size apartment garden, very practical when moving from an apartment or a city to another.
The bin can be placed indoor or outdoor depending on the outdoor temperature. A vermicompost bin is clean and do not smell bad when appropriately maintained. You may run into troubles, if the bin is inappropriate to the worms, when air and moisture are not sufficient or if dry (carbon) and wet (nitrogen) materials are not balanced. Indoors, you may also want to prevent fungus gnat or fruit fly in the bin by freezing food scraps before composting it. The worm bin can be placed in the kitchen, the best place to feed them easily and to keep your worms an eye.