I don't have an outdoor worm bin myself, but from what I've seen, they can be done pretty simply. Basically just a wooden box with a lid and some allowance for air flow. I don't think you need a "floor." You don't really need to collect or manage "worm tea" in an outdoor bin, because you can just use the dirt as a "floor", and any excess moisture will naturally infiltrate into the soil. You could even make a movable worm bin so that you can use that spot for planting in the future.

I don't think a worm bin would be a good way to process wood chips. Worms can't do a lot to speed up decomposition of wood chips in a bin; it's probably going to take the same amount of time with or without worms. What I see people doing, instead, is just spreading wood chips across the soil and letting nature take its course over a couple of years. Cardboard, leaves, and sawdust would all be good worm bin fodder. You say your food scraps are already being handled by indoor bins, but perhaps you could find some other "green" material to add to the outdoor worm bin, like weeds or grass clippings.

Recently I've been watching some YouTube videos by the "One Yard Revolution" guy and he talks a lot about using wood chips in the garden and seems to make a lot of sense. https://www.youtube.com/watch?v=YCtafUgoCX0

You're right, I would think that they would have a hard time processing the wood chips too, I wondered if they might aide in drainage or water retention though. I have a bed I placed too far in the shade and only have a few things growing (insanely slowly) in there. I might set up a compost on top of the middle of the bed (8*4) and let the worm juice soak into it then move the bin after the cardboard starts breaking down. I do love the wood chip pathways, they make my yard look ten times better and no mowing! From what I could see of the video (I don't have sound on this computer, will have to re-watch it later) it looks like the back to eden gardening method, is it similar to that? Anyway, thank you so much for the quick response.

Hi, parsley.... some advice on your wood chips. I put pine bark in my bins occasionally, but I do my best to break it up first with a very sturdy pair of pruners I can abuse. However, I have used big batches of old wood mulch in my bins before, and the worms seemed to love it. It does take awhile to break down, or may have to be sifted out and added to a new bin mix to finish off. The only cardboard I have ever had a problem with was a great big carpet tube a neighbor gave me. I wet it down, busted it up, added to a few bins, and the worms that didn't die avoided the stuff like the plague. Thinking on it, the cardboard roll was probably saturated in a boric acid solution to prevent bugs from moving into it while the carpeting was traveling from wherever..

The only other thing that I have learned NEVER to put in my worm bins is thermal paper type cash register receipts. They seem to be completely deadly to my squirm in any quantity.

Cardboard and leaves are great for an outdoor worm bin, although might be slow without some 'greens'. Perhaps some cut grass or weeds spread throughout. Wood chips would be better used as mulch or on paths I think.

Ouch, sorry, sustainabee, addressed my response to the wrong person. My bad.