My preferences for worm bins run contrary to much of what is on the market right now. If you search for a home vermicomposting system, you'll more likely than not come upon one of the continuous-flow type systems: the kind with stacking trays with vented bottoms. They're supposed to make harvesting the vermicompost easy: start with material in the lower bin, then when that is full add to the next level, etc. The worms supposedly finish the lower bin, then crawl up to the next layer for the fresh material, leaving black gold in the lower bin.
In my house, however, an expensive stacking vermicompost system is nothing more than messy, fruit fly-infested vermicide on the grandest scale. Why?
- The bins are too shallow: they dry out easily. Worms can handle too much water, but not enough is deadly.
- However, if you keep the bins moist enough, then any fruit fly within miles is immediately alerted to the brand new, multi-level condo created (they think, if fruit flies think) just for them. Again, the shallowness of the layers is the issue: you can't properly cover anything you put in.
- The worms don't cooperate, either. In my kitchen, the worms were just as likely to move to a lower layer than to a higher one. I was forever fishing live and drowned worms from the water-collection layer at the bottom of the unit. And a "finished" layer was still as full of worms as an unfinished one.
- Talk about a mess! Each layer has a grid on the bottom. When you lift up a layer, either to check on the worms or to harvest, you have a box with worms hanging out the bottom, and dirt all over. Where do you put it? You can't set it down, or you'll smash all the worms in transit from one layer to the other. So any time a layer was lifted, it became a two-person operation: one to hold the top box mid-air, and the other to work with the material below.
- And finally, the bins, in addition to being too shallow, were just to small to handle fruit and vegetable scraps for a couple who eats a lot of fruits and vegetables.
Does this mean you shouldn't vermicompost? Absolutely not! It's actually much easier, cheaper, and less messy than the expensive worm towers would lead you to believe. I just created a new vermicompost bin (will post pic right after this), but the old cheap bin I made from a Rubbermaid container is still the best bin I've ever used.