It should be fine and the worms shouldn't die off; they'll just compost less quickly. I've had worms survive a very long, cold winter (minus 20C for weeks and the bin frozen solid). When it got warm, they bounced right back. It looks like your bin is open to the ground, which is good. The only thing you might want to do is add a think layer of browns (leaves or cardboard) to the top - my theory is that this will provide some insulation and keep them active a bit longer; at any rate, adding lots of browns has worked for me. You can keep adding food during the winter, too; at some point, you'll want to fluff/turn, especially when it gets warm again, as the pile may compress or get matted particularly at the bottom.

Thank you loads!!

I have this same question - but it is my first season with a worm bin. Things are going along spendidly! I have an indoor bin, as I am in a cold climate. My question is, do I need to remove some worm castings before the long Minnesota winter? I don't really have much use for them this time of year. I started my bin in May, so it is about 1/4 full of castings and bedding. (and lots of hungry, active worms)
I guess my fear is that there may be too many castings by mid-winter or spring which may cause some kind of problem?? is this not a problem?
Should I make any changes before winter? separate and store some castings for use in the spring planting season?

I think it won't matter much either way, except for the convenience or inconvenience of separating castings in winter. If you put it outside now around your plants, it will still probably be useful to the same beds or plants you would use it for in spring, and might even be beneficial (some of the nutrients etc would get absorbed, and some biological activity still happens in cold temperatures). If you have an excess in the winter, well, you put it outside. Some bacteria and whatnot may die, but be useful to others, and many will just go into a quasi-hibernation and grow again in warm weather.
In other words, don't worry about it so much. I've put lots of compost out around plants in fall as a kind of mulch and by spring it's just part of the soil. These are mostly regular garden and perennials, mind. If you're going to be seeding/planting in spring, a big pile should also still be highly beneficial when you dig it up and use it in spring.
Keep in mind: there may be better ways and maybe this isn't perfect, but if you're mostly returning organic stuff to the soil, in the long run it should still be good for your garden.

I'm in the same boat as you Minnesota_Eric. I live in MN too and started my indoor bin in June. I probably won't start getting significant vermicompost harvest until around just before snowfall time.

Right now I'm just taking what I harvest from my flow-through system, and putting right back on top to keep the beneficial microbes/fungi/bacteria growing in the bin. Also any partially processed food can be fully composted by the worms.

We'll need to figure out a way to store our harvests through the winter, in a way that doesn't kill the aerobic bacteria - not in air tight containers.

I'll be eyeing future posts from you to see how to proceed...What type and size of bin are you using Minnesota_Eric?

Wow, I just realized this was originally posted a month ago...oops. Well mirendajean, if you're still interested, this guy makes vermicomposting trenches in his garden and keeps them going through his freezing Canada winters.

Read through this blog post, he describes his winterization process. I believe he mounds the trench with straw, then puts a tarp over it, then more straw.

http://www.redwormcomposting.com/large-scale-vermicomposting/the-vermicomposting-trench/

I didn't even think about the excess winter castings! I think I will harvest castings in October and lay it in my veg beds. I'll pile 3-4 inches of wood mulch on top for winter.

Thanks guys. This discussion helps a lot.

M

I think putting any excess castings / output and trying to 'store' in something like plastic is a bad idea - just put it outside. If you're really worried, dig a bit down and cover with mulch of some kind. Very little if any of the bacteria or other good stuff will be 'harmed' by the cold, but airless environments and the like have a high probability of causing problems. Dirt and castings are meant to be outdoors and they'll be fine there.

Thanks for the input...
I've got a 10 gallon, single bin system. (not a flow through)
The worms seem to be pretty busy eating up the bedding lately. Maybe I'm not feeding them enough... anyhow, the bin looks like mostly castings, so I'm tempted to harvest them, but I'm not sure that the castings would be as beneficial to my garden as they would be in the spring. Do the castings "store" well, or do they just turn into anerobic dirt after a few months?
I suppose I could use them on my indoor plants, but that's just not as fun !
I would think that the castings sold in garden stores must be at least a few weeks/months old, so it can't hurt for us to do the same???
I'm considering storing my excess castings in a separate plastic container (smaller rubbermaid) with a loose fitting lid in my basement. It would not be airtight, and it would be kept between 55-75 degrees until spring planting. The only unknown for me is if the castings would be more beneficial to add to my garden this fall, or to sit in my basement for 5 months...
Thoughts?

Minnesota_Eric: again, just my own view, I think the castings will be absolutely fine outdoors and beneficial for your plants. My guess is that it may even be good for them, as normal low-temperature stuff would go on, both before it gets very cold and even after - for example, normal beneficial fungi would start to colonize and share the resources with the rest of the soil and plants around it.
Note I have done exactly this - and by spring there is no sign of anything bad, and it just looks like rich, lush garden soil; the pile might go down a bit in size. The only 'warning' I can think of is perhaps to avoid places where it might get drowned in pooled water. Don't worry about snow or normal melting - that'll drain off quite well.
I've never tried storing except for piling outside. No issues with that. I suppose you could store inside but I think issues would be more likely to happen there - even with a loosefitting lid it won't be 'breathing', getting normal rain or draining like soil would in its natural environment. Inside you'd have to think about keeping it moist but not too much, etc, and who knows what the ideal is?
Soil and all the stuff in the soil are perfectly at home in your cold environment. (I'm in Russia and it's plenty cold too - even my worm bins are outside and the worms come back every year).

Thanks armoured! I'll consider mixing them in the garden too. I usually top off my raised garden bed with a few inches of compost in the fall, so I guess some worm castings under that should be safe...

Tell me about your outside worm bins... are they in-ground? How cold does it get where you are? How do they survive?

M-E: my 'worm bins' are regular compost bins, black sided, no real bottom to speak of. They are crazy with worms. It got cold enough last winter that as far as I could tell the piles were frozen absolutely solid (-20 celsius for good long stretches). As soon as it gets warm enough for the pile to thaw, the worms are there.
I can't tell you whether this is because the worms survive themselves or just lay enough cocoons, but they do fine and reappear every spring. I don't do anything much special to prepare things, but it's usually a pretty big pile by fall (two bins).
Now one big caveat: these are compost worms I found in a compost pile, so they're local and well-adapted. I think they're reds but they could be Euros. If someone bought worms from somewhere else the situation might be different. But in my case, I find them around the yard wherever there's wet rotting stuff like leaves. There's also an old compost pile for random stuff I don't put in the bin or for overflow, worms are happy there too.
I figure if the worms do fine their castings are hardly likely to be 'injured.'