My worm bin is about 2 1/2 years old now, surviving a second frigid Michigan winter in our unheated but "attached" garage, so I'm probably enough of an experienced old worm wrangler to give some advice and make some observations that may encourage you to start your own bin if you've been considering it.
First, worm ranching is not a demanding occupation. I've skipped feeding my herd a week or two, here and there, and they seem no worse for wear.
Second, you don't have to follow the books precisely to get good results. I've broken rules and made some new rules according to the path of "What Works is Good".
Third, TRUST me, you'll get over worm-squeamishness once you've held a few cold, squirmy handfuls of these quiet pleasant little workers.
Background
If you find the vermiculture link in the right column, you can spend some time reading my past worm ranching posts, and watch my amateur video about putting together my second bin after the backyard wildlife (I suspect Racoon. J'accuse!) destroyed my first box.
Where to Keep Your Bin
I am an advocate of keeping the bin in the garage. Where to keep your bin is something to consider if you live where there are animals who might break into the box (for worms or for vegetable scraps?) the same way skunks break into bee boxes. And in the Way of Permaculture, if the box is close to your back door, it will be handier to keep the worms fed.
I've read of other Michigan worm wranglers trying to keep their boxes outdoors covered by bags of leaves. That seems to be going to an extreme, to me. When the thermometer in my garage goes too far south, I stick a trouble light with a 40 watt bulb in the box to keep it from freezing solid. I can take a container of scraps out to that garage wearing my house slippers.
Another consideration for keeping the bin out of the house is the fear I've contracted from others who report they have inadvertently introduced the dreaded fruit fly. I hate fruit flies. I can successfully report no fruit flies, even after feeding my herd peaches and apples in the late summer and fall. My theory is that you need to be sure to bury such fruity scraps completely, and keep the damp surface of the bin contents covered with a few inches of dry bedding.
Bedding
Speaking of bedding, I've used dampened sphagnum peat and coir. I got an end of the year deal (years ago I stocked up at $1 per Brick! Score! at Meijers) before coir became a popular amendment. However, in the past year I've been using shredded paper - it gave me an excuse for buying a paper shredder - which even beats the price I paid for the coir. By tradition I avoid paper with colored ink and suspiciously 'coated' bills.
Catching the Worm Juice
Worm juice is supposed by some to be a smelly problem, but I guess my garage is airy enough that it hasn't bothered my delicate nose. I did figure out the best way to catch it is in a lid from a second box of the same size. I made my bin from a Rubbermaid bin, and put the bin on top of a second identical bin. (That bin can be used to store potting soil, etc.) There is window screen in the bottom of my bin, but I've read if a worm need to escape, he can get through even that.
An added benefit of this Bin over bin arrangement is that the worms are thus raised so I can feed them (and see them) without bending over by half. The drippings should be collected into a wide mouth canning jar occasionally to keep the messiness at a minimum.
To Feed or Not To Feed
Speaking of unpleasant odeurs, I've discovered the least tolerable smell comes from members of the cabbage and onion families. Those kitchen scraps go out to the compost pile. I also find my worms can't keep up with all of the orange and grapefruit peels Herb goes through, or the numerous corn cobs in August. So I compost citrus peels and cobs. All other vegetative scraps go to the worms, along with tea bags and egg shells. I've read that worms like to lay their eggs in the interior of egg shells, so I don't go crazy trying to crush them.
Here I'll quote an interview by Bob Forbes with another worm wrangler from a program handed out at the 7th Annual Spring Horticulture Show put on by the MSU (Michigan State) Horticulture Club, that was in my Neverending Pile. I completely concur with this advice.
"Books and articles on this subject talk about burying garbage at selected locations in the bedding and rotating or alternating between these locations. This gives you the impression that the worms live in the bedding, coming over to the "buried" garbage for meals, and then returning to the bedding. I have not found this to be the case. I think they hang out in the garbage all the time. So I put some bedding in when starting the bin to give them a place to live, and after that I don't worry about maintaining the bedding. I also don't worry about alternating Where I put the garbage, or even mixing it in..." Here he adds ... "or burying it" which I disagree with, but then, he has had fruit flies and I haven't.
This quoted technique eliminates the need to figure out a system of marking the last scrap burial, and the worms don't seem to mind.
Finally, Harvesting the castings
Here I quote again from the above interview, and again I agree:
"The production of castings ... has fallen a little bit short of expectations. As with other kinds of composting, the volume reduction from start to finish is tremendous." I recommend harvesting a bin like mine only twice a year, ideally - in May and September. The spring harvest renews the bin and provides castings for spring planting, and the late summer harvest renews the bin, but gives the worms enough time to get comfortable before the harsh temperatures slow down their activity in the bin once more. A single midsummer harvest will work too.
To harvest castings I turn the whole bin over onto a large tarp which is spread on the garage floor. The western sunshine streaming in the open garage door keeps the worms digging for damp cool shade, making it easy to separate the worms from the castings.
The process is as follows: The sun lights drives the worms down, I scrape off a layer of castings, the uncovered worms dig deeper, I scrape off another layer, until we scrape tarp. The worms are pinkish red and easy to see. They are different sizes, babies to adults and some will be overlooked, but there will be enough to restart the bin.
Renewing the Bin
I put a small amount of damp bedding and some of the old castings, including unprocessed scraps, into the empty bin, and put the mass of worms back into the bin where I feed them, and cover all with dry bedding.
If, as I suspect, there are any tiny baby worms and eggs, or escapees in the castings, then using them in the garden in midsummer can only be beneficial to the garden and give the worms plenty of time to get used to living outdoors, so they can dig down into the earth as they should in the fall to survive the winter.
