not even worth thinbking about on the scale of a 'worm factory' .... hot composting takes a large volume [a cubic yard is minimum, 3'x3'x3'] and close management [not to mention turning], and bacterially generated heat is a very fleeting thing, difficult to maintain in single digit temps at all, let alone more than a few days ... aside from the fact that worms don't move a noticeable distance in a short time

the best way to deal with home food waste vermicomposting is to keep the operation indoors, usually something like a 17 gal rubbermaid bin in the closet or basement ... if you're wanting to generate a lot compost, hot composting is the way to do it, but in Montana that'll be a summertime activity

Bill

Keeping them inside is out of the question, per my husband. My worm bin will live in the greenhouse, and daytime temps will be fine out there, even when it's below zero. I just need to keep them warm enough at night not to slow down activity...that's all. There really has to be a fairly simple way to do that...I'd just prefer not to heat the whole greenhouse all winter if possible.

I'll keep looking around...it was just an idea. :-)

I've read that some people use heat tapes made for the soil. Others have used a glass container w/an aquarium heater in it to keep an area of the bin warm. Both I think would be inexpensive ways to keep a bin alive during the winter so you could pick up the pace again in the summer when your bins naturally warm up with the weather & you need them more for thier purposes with gardening and scraps.

I've not tried either myself as I just started & haven't overwintered, however I plan to keep mine in the garage or basement & hope the temps are tolerable there for them.

I had the same thought at one time as well- in regards to maintaining a "warm bedding bin". I agree with Bill (squeeze) that it just isn't practical- especially in the dead of winter. You should convince Hubby that keeping them inside would make you the happiest Wifey on the planet. And what could be better than that??!

The argument didn't work completely with my wife either so I do keep most of my worms outside in a shed. I wintered them by using a two plastic half barrel configuration. Each bed uses half of a 30 gallon and half of a 55 gallon.

I built a wood frame around the 30 gallon half so that it could rest suspended inside the 55 gallon half. I then filled the 55 gallon with water to about half full and installed an aquarium heater. I insulated the whole thing in newspaper. A 50 watt heater keeps it good down to the mid 30's, the 100 watt was good down to the teens. Below that, the worms just got cold, but never below 50 soil temp. I could have used a bigger heater- just didn't see the extreme need.
If the temps get too high, the lower bin can be filled with ice to cool down the soil with out adding water and soaking the bedding.
As suziqzer eluded too- there are many ways to do it. This was just another way and it works for me.

My worms inside were much easier to maintain and if possible, it is the better way.

if you're stuck with the greenhouse the best way would be to use a regular bin and dig it into the ground with a couple of inches of insulation around the sides and an insulated cover added overnight ... the problem with that sort of situation is it's not the ambient air temp that counts, it's the average bedding temp, the air temp may be "fine" during the day, but once the bedding temp falls, a few hours of warmer surrounding air during the day doesn't change it much, the worms will go as low as they can to find a stable temp, and activity drops to near nil

you need to maintain as constant a temp as you can, and "ideal" for active decomposition is above 60° minimum ... "freezing" the worms isn't the problem, they'll cast cocoons if they're faced with extreme conditions and repopulate in the spring, but if you want to use them for waste disposal, they won't be active once the bedding temp drops

I do a lot of hot composting, and there's always worms in those piles, around the sides and lower down - in the winter when it's hard to maintain the highest temps, the worms head to the bottom - in the worm bin, which is ~4x8x4' deep, on the ground, and is fed with the "finished" hot compost, when nights are repeatedly freezing but days are still above, the worms retreat to bottom center of the bin and not much happens, I lay lots of compost on top and let'em be

Bill

Thanks all. I can't "dig it in" either - we have a major bindweed problem, so everything under the mulch bed of the greenhouse is covered over in weedmat to prevent bindweed from sprouting. Due to an earlier problem with little flying bugs (larger than gnats) when I was breeding mealworms for my lizards a few years back, hubby has put his foot down about any more bug, insect or worm facilities anywhere in the house. I really would rather have them in the house, but hubby already puts up with a plethora of plants and pets he doesn't really want...so I doubt I'm going to get anywhere with pleas on this one.

I did some research over the weekend, and it looks like heat tape and a seedling mat at night will keep the soil temps warm enough to keep activity going through the winter (I should be able to keep the soil around 70 degrees all night). The greenhouse heats up to around 100 degrees by noon on even the coldest sunny days in winter, and there will be automatic vents installed by then to open when the ambient temps reach 68 or so, which will keep it cool enough in the day not to cook the worms, but warm enough to help keep the soil temperatures between 65-80 degrees. The heat tape/seed mat should cover the cloudier days (when it might only heat up to 70 or so in the greenhouse). The heat tape and seed mat will be on a thermostat to bring them on automatically whenever the soil temps fall to 70 degrees. I'll construct a "box" out of foam insulation that will be just slightly bigger than the worm bin to place over it, and keep the heat radiating off the bin from going too far - that should help hold the soil temps a bit more steady.

It will be much like heating reptile tanks, actually...so I think it should work just fine, as long as I keep a close eye on it. Heat tape and seed mats are cheaper to run than my space heater too...so I should be able to wait until March to start that up again as well.

I'll try it, anyways...if nothing else, they certainly won't freeze, and the worst thing that could happen would be that activity would slow down so I couldn't use it in the winter. And I can always run the greenhouse heater on the coldest nights to "help" the heat tapes out.

Now are the low night temps this summer going to be a problem for the bin? It will drop into the 40's and 50's for awhile yet here...I keep the greenhouse heated to 60 overnight now, do I need to turn that up for the worms overnight? Once the temps warm up, I was planning on putting the bin outside for the summer, in a shady, cool spot.

Thanks again for all the suggestions - the bin should get here this week, I think...and I have the "Worms Eat my Garbage" book scheduled to be delivered tomorrow, so everything is looking good! :-)

Jamie as Bill could tell you I went overboard with the temp thing when I started. I think you are doing the same. If your goal is to keep the worms happy and grow a bigger herd save the money on electricity and buy a few more pounds of worms. If the temp drops enough so your worms slow down by two thirds your will still be processing as much waste. And the herd will grow even faster.

I have tried the water heater and used the heat tape. The heat tape is much more efficiant than I could have ever hoped. In a 15 sq foot outdoor bin the 85 watts of soil cable was more than enough to keep the bin above seventy even on nights that were only in the teens teens. So using my estimate you wont need more than 6 or 7 watts per square foot of bin.

Hope that helps.
Darren

gauge what you need by what happens this spring and summer nights, sounds to me like you're setting up a slow cooker .... also note that you need to get on to prepping some food for them, the waste takes time to become microbially active enough they can use it, they're not vegetarians that like it fresh .... and let us know how it goes :)

Bill

Darren, that helps a bunch, and I appreciate it. Heat tape is what I'll plan for, assuming my wormies survive the summer. My goal is simple - just to keep the bin operating year round, so it keeps processing junk mail and kitchen waste even in the colder months. Since there are more cold months here than warm, it makes no sense to even have one if it's just sitting there frozen all winter long.

Thanks Bill - that's what I've read, and I have some kitchen scraps set aside already for the bin. I have plenty of newspaper, corr. cardboard, and junk mail, so whenever the bin gets here, I'll be ready to set it up with food & bedding to sit there "getting yucky" until the worms arrive. :-)