I’ve been looking up vermiculture (worm composting) recently – I found that red wigglers, the kind of worm used most frequently in worm bins, are an invasive exotic in the great lakes region. However, freezing compost before using it will kill any worms in the compost – so, as long as care is taken, it’s still a pretty awesome way to compost.
But what method to use? Some people just use a plastic container and mix it once in a while. Others like a similar system, but you only use half the container at one time – when you’re done with one half and start the other one, the worms will theoretically migrate from one side to the other over the course of a few days. A very popular method uses at least three containers – two top containers to put compost in (C1 and C2), and a bottom container for the ‘worm tea’ (C3). In the tower method, when the top compost (C1) is becoming mature you switch it’s place with the middle container (C2), then place bedding and scraps in C2 (now the top container). Both containers have holes drilled into the bottom. As the compost in C1 matures, the worms will, theoretically, migrate upwards into C2. Repeat ad nauseum.
I think it would be very neat to incorporate the mesh screen into a vermicomposting bin, a la these guys, so that there would be no worry about transferring worms to the garden from the compost. I’m not quite sure how that would work… right now, the best I can figure is that the compost could be shaken through a wire mesh screen (maybe 1/16″ spacing?) as it is removed from the bins… anything that doesn’t make it through can be dumped back in.
Finally, this guy is my new favorite.