Saturday, January 31, 2004

Earthworm 911

OK, we’ve got a serious issue to deal with this morning. Diane posted a comment yesterday about her worms, which have apparently failed to thrive in what sounds like a lovely new stacking worm bin system (maybe the terrific Wriggly Wranch bins that San Mateo county sells to residents for a bargain price of $29?)

Anyway, Diane, it sounds like you’re off to a good start. You ordered your worms from a worm farmer rather than digging them up out of your backyard, which means that you probably got the very best species for worm composting, Eisenia fetida, the redworm or red wiggler. You also got one of the best bins on the market. So what went wrong?

Diane says:

“It all started when I tried to get them to move to the upper layer of the bin, once they got near the top of the bottom layer. It was not a successful attempt and I gave up, removing the upper story of the mansion and going back to letting them exist in the bottom floor which seems to be what they prefer. Is it too cold here? Sometimes I wonder (we are in San Bruno on the edge of Pacifica.)”

Hmmm…well, first of all, you shouldn’t have to encourage the worms to move to the next tray in the bin. As they eat and their tray fills with castings, the contents of that tray will rise to meet the bottom of the next tray, and the worms will find the holes in the bottom of the tray and move up on their own. There’s really no need to move them around yourself.

I wonder how long you’ve had this bin. I tell people to give a stacking system like this a year. You’ll start out with just one tray and feed the worms slowly while they build up their population and get used to their environment. Keep a layer of shredded newspaper on top—that will soak up excess moisture in the bin , keep pests out, provide a food source, and help ensure that the contents of each tray are in contact with the tray above it.

It might take a few months or more for that first tray to fill up. Then you’ll put the second tray on top, start adding food there, and the worms will gradually move up into it. You’ll continue this process until all three trays are full of worms, castings, and food. Then, and only then, is it time to remove the bottom tray, use the castings, and put it on top to start over again. It can take several months or even a year to complete this cycle the first time. After that, it’ll go faster. I probably rotate the trays on my bin at least 4 times a year now.

Diane, you probably won’t be surprised to hear that I think you should buy another pound of worms and try again. But before you do, let’s figure out what went wrong with the last batch.

Tell me a little more about what happened. Did you start them out in a bedding of coir (shredded coconut fiber), which usually comes with these bins? What have they had to eat? Where is the bin? I doubt it’s too cold where you are—worms usually do fine in our cool northern California winters. They’ll certainly slow down their rate of growth, and they prefer a temperature in the 60-70 degree range, but my worms tolerate temps in the 40s, with occasional dips into the 30s, with no problems.

And are you sure they’re dead? Did you find dead worm bodies, or just no worms?