It pretty much comes down to freeze tolerance. Many vegetables (like peppers) have none. So the way to ensure survival is to keep temperatures above freezing. Now, peppers won't do particularly well when it's cold, so for them you really want warmth. That's going to be a lot harder.

Insulation isn't going to help unless you have a heat source. In that case, the insulation just slows the heat loss. If it's cloudy, you won't get much heating from the sun. Even then, letting light in without letting heat out is going to be challenging. Compared to grow-lights, heaters are really cheap. Sorry, but peppers in winter in 3b without a lot of additional heat sounds like a non-starter.

Of course once you have peppers, you can pick them anytime. They may not have time to get very big, or change color, but they're edible.

Don't know about "cheap" as you seem to be going to a lot of trouble already. If you open the garage door daily for your car, heat will escape. Not very realistic without serious heating and expensive lighting, they won't grow unless it is warm.

You might be better off just trying to keep the plants alive dormant, to grow next Spring. Youtube has videos about people who overwinter pepper plants, maybe look at some of their strategies.

Overwintering the plants might be a sensible strategy for someone with a short growing season. That way, the plants are mature and ready-to-produce when the weather gets warm. Pepper DTM is 60-90 days, and that's in thoroughly warm weather. The growing season you quote is frost-to-frost, and only a fraction of that is available for really growing peppers.

Well, I'm thinking that that's the situation the OP is in right now. Bought new small pepper plants in the spring, and the growing season wasn't long enough to mature the plants and then produce full-sized fruit. So you need to start out with more mature plants in order to get a head start on a short growing season. Overwintering could allow that. A more compact and likely more economical way is to make a heated container for small plants a month or two before last freeze, and mature the plants in that before summer. Might not be able to find small plants well before that last freeze though, so this might be a seed-your-own proposition.

If they were in pots they could be taken indoors to a sunny window sill.

I had no idea peppers could be overwintered.

Formally, peppers are tropical perennials (as are tomatoes). But they are treated as annuals most of the time because they are cold-intolerant. They can live for several years if treated right.

Have to balance the amount of time,energy and effort, attempting to overcome natural circadian rhythms of plants and people. Better to start sowing hardy plants to overwinter without supplemental heating (and the inevitable increase in pests and diseases). It's not like the autumn/winter is devoid of interest or gardening tasks.

Seems to me that what you need is a free source of heat; other than the sun. There was a fellow near here who grew vegetable seedlings to sell. He had heated greenhouses with oil heat. The oil came from local garages. He towed a trailer around and collected the oil that was drained from cars and trucks. There's also firewood but that'd be more work than the used oil. And it's more reliable running oil into a furnace than getting up all night to feed a wood furnace.

I need to say that if you're thinking about grow-lights, a thermostatically controlled electric space heater is real cheap by comparison. I see kW ones out there for $30. If you're just heating a small and reasonably well insulated greenhouse, that should be economical. Yes, you'll probably need a fan at the other end to circulate the air. Otherwise it'll get hot at one end and stay cold at the other. That all being said, this sounds like an arrangement that is going to require a lot of supervision, and ideally a couple of thermometers. Peppers are actually hot weather plants, so a cold climate just isn't well suited for them, Commercially, Alberta peppers are entirely a greenhouse project.

Buying new plants in the spring isn't necessarily a credible strategy. I suspect that's what you did. Your problem is just that your growing season is too short. Makes one wonder why people are even selling them there.

There comes a point when you need to just cut your losses and learn from any mistakes you may have made. There is no cheap way to basically create a whole grow room with artificial lighting and with the supplemental heat that would be needed in a frigid, unheated garage. The equipment alone is costly but you also have to take into account that your energy bill is going to skyrocket (and they are already talking about energy costs being higher this winter). Assuming the pepper plants are still alive it would be relatively easy to bring a few into your house to overwinter. Otherwise, just spend this winter doing some reading and make a plan for next year.

For example, you can plant your warm season crops sooner next spring by using cold frames or plastic over hoops, and these can be reused in the fall to extend the season when there are light frosts. Using black plastic over the soil will also help to warm it up sooner. If you aren't already using them then raised beds tends to warm up faster, or if you are growing in the ground consider using mounded rows where you intend to plant. Oftentimes plants grown in pots tend to mature quicker than those grown in the garden. If you bought these peppers as seedlings, perhaps try growing your own from seed and choose short season varieties. Or if you started them yourself then start them earlier so the plants are more mature when you put them in your garden...

Rodney

I'm not sure that survival temperatures are the answer here. This isn't about cold frames and black plastic, which pretty much just protect from freezing. It's about getting the major warmth that peppers need to grow well. We're talking 70-80F+ or so. Below 50F, they simply won't grow. Most other crops will do adequately at low temperatures. So creating a grow room in a freezing garage for peppers is going to involve making and keeping a lot of heat. But a strategy of growing them indoors in large pots, getting them close to maturation before putting them outside, perhaps by wintering over, may be the only way to go with a short outdoor growing season. Even then, big plants indoors need lots of lights if you don't have a very sunny window.

I pretty much said that trying to grow anything over winter would be folly.... My suggestion for cold frames or plastic covered hoops (low tunnels) along with black plastic on the soil were for next spring and I never claimed they would allow for peppers to be planted 2 month early. But they very well could allow for planting a couple weeks earlier and would also extend the season in the fall another 2 or 3 weeks. That would effectively give an extra month of growing and in a short season area that's a heck of a difference. And with hoops in place then once it does start to warm up the plastic can be switched over to row cover which would provide an even better growing environment for the peppers (or other warm season crops).

Rodney

I guess my point was that if you have 50F in your cold frame, two weeks on either end aren't going to make any difference for peppers. They'll just sit there. Though maybe one can manage 70-80F in a cold frame? But yes, trying to grow peppers in 3b winter is going to be tough.

Eliot Coleman is pretty well known for organic growing. He lives well north in upper Maine and manages to grow enough food to have his own farm stand. Very innovative and experienced. All his books are very instructive. Here is a link to his book on Four Season Harvest....

Four Season Harvest

I don't know if he grows peppers or if his hoop houses extend the season for them. But to me he is an authority on extending the season.

Greenhouse is a good idea. That said sunlight decreases a lot and even with heaters you get little sun and the sun you get is weak beause of the time of the year. A note on peppers. Yes freezing kills them. They do better in Ohio in October then most things in my garden. Sure onions, lettuce leaks are fine but peppers do better then corn, squash, tomatoes, melons, beans - almost everything. I have a homemade greenhouse I put over them and put in a heating matt. I pick my last round in mid Nov to early Dec. It is amazing how good they look in early Nov compared to 80% of other things in my garden.

Eliot Coleman does not attempt to grow warmth loving veggies in his winter hoop houses; it would be an exercies in futility. He focuses on plants that can handle quite a lot of cold--greens of many types, carrots, parsnips, etc. The key to success is getting the plants to reach maturity before cold and short days stop growth. Then they essentially hold for weeks until they are harvested. His books include info on how to figure out when to sow various crops for winter harvest. I highly recommend his books

Exactly so, Laceyvail. My friend has a small (50acre) council farm where he grows vegetables to sell on a weekly market stall. Right now, he is selling hardy root vegetables, greens and such...and sometimes buys less hardy fare from giant greenhouses in the SE of the country, just for variety. Do you know of the 'hungry gap'? That period of time in late Feb/March, when winter stores are exhausted but it is too soon for early crops to be picked? While 4 season gardening is not really possible, even in a temperate climate like ours, careful storage and preparation does mean no-one is likely to starve, but there isn't much in the way of fresh vegetables to be had.

Essentially, it is a fool's game, to grow anything which is unsuited to the climate and geography of the growing location. It isn't like there is no variety or choice, even with restrictions. It is also environmentally damaging and ecologically foolhardy to grow ridiculous crops just because we have all got used to a global trade.

There is not really anything environmentally damaging and ecologically foolhardy about growing peppers in a cold climate. While heating a greenhouse with non-renewables can be viewed as somewhat damaging, the same can be said for burning fuel to bring peppers up from a warm climate to a cold one. The real problem here is just the trouble. You spend a lot of time and effort fighting the cold, and cold-intolerant plants make it so much the worse. So if time and effort is an expense that you find desirable, go for it.

Growing unseasonal food in an inappropriate climate always carries an environmental cost. - regardless of whether the issues are excess fossil-fuel produced heating or transport costs or water use. As you say, food-miles and carbon footprints are interlinked. Obviously, ymmv, the equations regarding food production are complex and you always have to balance the use of resources (especially water and land use) but to pretend there are no environmental consequences is disingenuous. I remain unimpressed with the urge to consume tomatoes for 12 months of the year...given the horrendous agricultural crimes being committed in our quest for exotic foodstuffs. Having said that, I am as guilty as the next person since, in common with the entirety of the developed global north, I consume an inequitable amount of resources. Always worth considering what we can and cannot do without though.

It's part of a bigger conversation about self sufficiency and sustainability. Something I find quite challenging to think about in a meaningful way. Few of us are in a position to be self sufficient but since it might be required of us through no fault of our own at some point, I am considering it something to think about sooner than later and plan what is possible.

And whereever we live, few of us can grow our own food 12 months of the year. I live in New England where the last of the garden produce has to be harvested in my garden by late October and wont be available again until the end of April or later the next year. So that is 6 months of the year, without home grown food.

I am looking into growing indoors over the winter. I've already started dragging books home to explore the possibilities. I have a book out right now that I really like that seems to be right on the mark, well organized and with clear direction. 'Indoor Gardening the Organic Way' by Julie Bawden-Davis.

Is that going to use up too much resources? I can't see how it doesn't factor out in favor of doing it, since the resources used across the globe to grow food, harvest it, transport it to my local grocer have to be astronomical in comparison.

No, I'm not going to be able to grow tomatoes indoors, especially in my house without any south facing windows. But greens, microgreens, sprouts and a few other choices, look doable. I'm even thinking I could grow some of my peppers in the summer in pots and drag them into the house and extend my season that way.

Of course, the other way to go, is to grow enough during the growing season to put up food to cover the winter. I highly doubt most of us could accomplish that since I'd think you'd have to have a pretty big property and garden to have enough to supply you with your own food over the winter. Dried beans, potatoes, canned food, frozen food, dried herbs. Maybe even dehydrated. Still, I think it's worthwhile to make the attempt to do as much as you can and know you will be able to do that if you had to. But it is a big project to take on.

Right now, most of us are not in a position to go back to 'pioneer living', [g] or have the inclination to do so, but looking at the news on any given day, it wouldn't shock me if we find ourselves in need of doing something along those lines in the not so distant future.

Your point was that growing unseasonal food in an inappropriate climate always carries an environmental cost. That's hard to argue with. But my point is that just EATING unseasonal food in an inappropriate climate carries many of the same costs. Just acquiring that food entails transportation costs, which are likely to be substantial and could well be comparable to what it would take to heat the plants that would produce it in a cold climate. So if you've decided you're going to eat unseasonable food, you're still going to have to digest environmental costs one way or the other. In fact, if you don't live on a farm, eating most anything involves extra environmental costs. So I guess your argument would be that if you don't live on a farm, and want to be wholly environmentally conscious, you'd better not eat.

That all being said, I don't think one gardener in a cold climate is going to destroy the environment by trying to grow peppers. You should understand, by the way, that farmers DO grow peppers in cold climates, and they're doing a lot more environmental damage that this one gardener would. You might want to check out the Pepper Farm of Alaska. See also ...

https://www.adn.com/voices/article/lowenfels-growing-peppers-alaska-worth-effort/2013/03/21/

Yes, that was the point I was trying to make too. Even taking into consideration, some use of electricity or heat to grow crops in a cold climate, for an individual growing their own food, they do have to eat, and that is probably still more efficient than buying food grown commercially and transported everywhere and grown organically, it's the healthiest option too. And if you can grow crops that require little intervention by fuel or electricity, and had only a few plants that demanded the same, you're still ahead of the game. And processing food from the summer garden for the winter, puts you ahead even more.

I would think we are a long way away from doing that as individuals right now, for the most part.

Another technique from the past, was to build 'hot beds' in the garden in colder climates and this method is heated by decomposing compost, so no cost there.

How to Build a Hot Bed

Well when I'm in Canada I like to eat what ever is in season as if I was an Indigenous member of the Nishnawbe Aski Nation. I will hunt and gather everything I need locally from nature and will not consume any imported foods. The deer, elk. fish and moose I consume are all organic and as healthy as nature intended.

Kevin - That is so far from my life experiences, it sounds amazing. I've never even eaten wild game. How long a period of time do you stay in Canada? So you don't eat anything other than meat?

I live in a climate with a short growing season and a cold winter. I heat my house primarily with a greenhouse I attach to the south side of the house in October and remove in May. It allows me to grow and harvest leafy salad veg and fresh carrots in winter, and to start vegetables early in spring with strong sun exposure. I still wouldn't try to grow peppers in here through winter, because the nights are below freezing all winter in the greenhouse.