We’ve had red wrigglers in our Gusanito tiered worm compost bin for almost a year, and it’s been a mostly successful project aside from the occasional pot worm invasion and one “recharge” during a winter cold snap (had to buy a second batch after the first pound, um, disappeared).
Here are five things we’ve learned along the way.
1. Half and half
We try to keep the ratio roughly half brown stuff (shredded brown paper bags, no ink) and half green stuff (veggie scraps). Some people use dried leaves for their browns, which in our experience takes forever to decompose. Another good thing about brown paper is that it soaks up a lot of the moisture that’s given off when the greens are breaking down. If the compost starts to look too wet, add more browns. If it looks a bit dry, add more greens.
2. Leafy greens
Our worms subsist primarily on chopped-up leafy greens – spinach, lettuce, carrot tops, herbs, etc. We don’t put in any fruit just because decaying fruit smells pretty god-awful in the trash, so why on earth would we leave ‘em out on the balcony? And anyway, it will probably attract flies and gnats. Also read that fruit (especially citrus) can make the bin too acidic. We’ve fed them squash a few times, but that tends to lead to lots of tiny white pot worms, which aren’t necessarily bad for the bin but I get a bit squeamish when there are hundreds of these little white things squirming around.
They say you can feed worms coffee grounds and used tea bags, but we dumped in some coffee grounds once and that also led to a major pot worm invasion.
3. Eggshells
We add a tablespoon or so of ground-up eggshell with every feeding. The calcium helps keep the bin from getting overly acidic and the grit helps the worms digest. We just save our post-breakfast shells, rinse and dry them out, then grind them down using a mortar and pestle. (A blender could probably do the same.)
4. Slow, steady feeding
When we first started the bin, we had a tendency to dump in all or most of our veggie scraps; after all, a big part of composting is to reduce what goes in the trash, right? Well, that quickly ended up in a moldy, wet mess, with worms climbing up onto the bin’s walls and seeking refuge under the roof. Now we feed them smaller amounts every few days. For example, yesterday we added about a cup of spinach and a big fistful of shredded brown paper in an even layer on top of the existing compost; in two or three days, that will be decomposing nicely and we’ll layer on some more food and paper, and so on. Some experts suggest burying the food to prevent flies from hovering around and to keep out odors, but we haven’t had any problems with flies or funk – yet, anyway.
5. Leachate is not worm tea
Contrary to what many might say (including the Gusanito manual), the liquid that collects at the bottom of the bin is leachate, not worm tea, and shouldn’t be used on plants. Leachate is produced when excess water is released from decomposing wastes; it doesn’t have anything to do with the worms. Worm tea, on the other hand, is what you get when you steep the finished compost in water and pump oxygen into it to stimulate the beneficial aerobic microorganisms.
There are lots of resources on the Interwebs about worm composting. Here are some of the key sites:
Wondering where to get worms in the L.A. area? We buy ours from Alice at Happy Camp Worms, a home-based “wormery” in the San Gabriel Valley. Email is happycampworms (at) yahoo.com. She’s awesome and highly recommended.