Icky Worm Girl speaking. This is my Worm Factory, which I’ve maintained for just about a year and a month. It has five trays with mesh bottoms. You bury food scraps under the bedding on top, and as the trays fill, the worms migrate to the upper trays. After a couple months, the bottom tray is completely black and well composted. Since everything is buried, the only smell is fresh earth.
My one problem has been fruit flies. I think I finally have a strategy to control them, but they never completely go away. To prevent them from breeding, you have bury your kitchen scraps deep. To catch the ones that show up anyway, you have to trap them. A jar with a bit of fermenting sugar water covered with slightly perforated plastic wrap is remarkably effective. And disgusting.
So I’m not going to see you that. I’m going to open up my worm bin and look inside. (ICK ALERT!)
The first two levels look pretty much the same. For the bedding, I use a mix of leaves and shredded paper. This topmost tray is dry, to discourage the fruit flies. I bury the scraps in the second tray, and keep it covered with bedding. As the moisture in the scraps wets the bedding, it becomes damp enough for the worms to come up.
I know you’re supposed moisten the bedding for the worms to come up faster, but until the fruit flies are gone, I’m holding back.
The middle tray is where you start to see some worms on the surface. The main evidence of their presence is the darkening of the bedding with worm castings. From here down, things get moister and earthier. In fact, the drain at the bottom is dripping excess moisture (worm “tea”), which is how I know the stack is moist enough to cycle.
As you go deeper, the fourth and fifth trays both have lots of worms. In the bottom-most tray, the bedding has been eaten, and so have most of the scraps. It’s composted.
Since I’ve been stacking the trays in reverse order, this is now on the top, and the worms are trying to get away from the light. I scooped off the dark stuff to harvest it, letting worms go into the next tray. Once it was empty, I removed it from the stack, put the other four back where they were, and set the empty one on the top. Then I filled it with dry bedding, and the cycle continues.