I am going to try it this year. I have very nice big green leaves of bok choi, kale and some other Asian variety. I put two low tunnel hoops and plastic sheets. I do not think that they survive during the winter though because of the freeze thaw cycles. But it may help to keep them longer, we'll see for how much longer exactly.

Peter, whether or not you try to over-winter, as antmary says, you can definitely extend the harvest for quite a while. Also, as you already pointed out, any bed that is raised above the ground will freeze faster than the surrounding earth (conversely, it will also warm faster.) As you said, You can use compost around the outside of the bed, and as a mulch on top of the soil around the plants as an insulator, but you can also use leaves, hay, or straw bales.

I picked the last of my peppers just yesterday. I covered them on the coldest nights, and (this is another trick) put hot water in containers under the row cover. If you have a fireplace or woodstove, you can do the same thing with hot stones. Harvested 15 extra lbs. of cleaned, seeded peppers that went straight into the freezer.

As far as when to cut it... harvest some early, and wait on the rest. Turnips, kale, mustard, and many other greens (such as some spinach) will survive in a covered bed long into winter... sometimes until the next spring. Some of these plants, as you may be aware, produce chemicals that act as an antifreeze.

Let us know how it works out.

It can overwinter, if the weather will be reasonable. But do not use plastic - use agribon or any other cover specially for cold weather. Make sure it is loose on the hoops - good snow can rip it if it is tight.

I have this:

http://www.rakuten.com/prod/dalen-products-5ft-x-25ft-harvest-guard-floating-garden-cover-hg-25/205673548.html?listingId=410603262&sclid=pla_google_FarmandHomeSupplyCenter&adid=29963&rmatt=tsid:1012713%7ccid:232720129%7cagid:13676215369%7ctid:kwd-84696839689%7ccrid:60879539929%7cnw:g%7crnd:506809406749797521%7cdvc:m%7cadp:1o5&gclid=CIeRxoLposkCFU8XHwodMgILuQ

I would really like to give it a try to have it form heads in early spring, but not if I am wasting my time. Galinas you are in a colder zone than me so I am encouraged. You have done it before? Simply extending the harvest for so little lettuce doesn't have much point.. we could eat that in less than a week, or for Thanksgiving.

I am also hoping the carrots will have something decent for me in the Spring... but I know those are much hardier.

I have always had success overwintering lettuce. My hoop houses have Home Depot Paint section plastic. I have used cold tolerant leaf lettuces (mostly romaine or speckled types), a selection from Territorial Seeds. Do not mulch the bed itself, as the soil helps with thermal ballast, but only if it is uncovered.

The Romaine is supposedly cold tolerant according to Johnny's. The lettuce is Muir and not labelled cold tolerant. Both are heat tolerant -- which is required to get the lettuce going in the summer -- these were planted like August 1st, but grew so very slowly due to the lack of sun my garden gets in the Fall, and as you can see in the photo are nowhere near full size or heading at all.

Plastic would definitely hold heat much better than the Harvestguard... the Harvestguards are very thin and I don't think would do much. But I would think you'd want it to breathe... I was in a plastic high tunnel without ventilation and it is nasty in there.

what do you mean breathe? plants breath CO2, which comes out of the soil. hoop houses have been used for decades, they work in winter without ventilation.

I would and do use frost cover material and top it with plastic as the weather gets real cold. Harvest what you need through the winter leave some till spring. I make sure soil in moist when covering. unless it gets real hot I would leave it alone through the winter. greenhouse plastic is best but 4 or 6 mil clear plastic will work and is readily available and cheap.

You could add a string of those old, big bulb, Christmas tree lights for some warmth. I used these last winter for some tomatoes. Worked great and you can find the lights now with the holiday coming up. Ace often stocks them. Good luck!

Peter,

I used Dalen as a cover but in 2 layers directly on the plants. And painter plastic cloth on the hoops. As a temporary protection. Didnt try for overwintering.

I don't think the Dalen will work by itself for overwintering -- it is too flimsy it won't hold the weight of snow, unless I add more hoops.

glib, I was at a farm and was in a plastic high tunnel and the air was really dank in there, and he said his experience is the plants don't do as well without ventilation, and I definitely believe it - even the weeds growing in there looked very unhappy. But, in this case, I am just trying to get them to survive the winter not thrive.

I think I am going to put the Dalen and then top it off with plastic when it gets really cold or snow is forecast.

I've also got artichokes I wanted to try to overwinter, I asked in another thread and got no response -- would covering them possibly help?

My lettuce overwinters every year under one layer of Agribon-19 (and, of course, lots of snow at times) and I'm a zone colder than you. I don't think you can be guaranteed heads (I only do leaf lettuce over winter, so no experience) but it certainly seems worth a try.

It will eventually freeze and die and here are the reasons.
You don't have enough thermal mass under cover to give off heat at
night. It will last into December or even early January (depends on
your weather). Lettuce can only go through so many freeze-thaw cycles
before it gives up. The likely hood of you able to produce full sized
heads in the spring from these plant is highly unlikely. They will also
bolt much faster. You will be better off to start some lettuce and
transplant it in March and that will be your new spring crop.

A
couple good things, get the row cover on now and plastic now. Just be
concerned about overheating on sunny days. Also your plants are small,
the smaller they are the better they do.

Here is some of our January/February lettuce. These images were taken on November 6th.

Jrslick, I would tend to think you are correct, but a number of other posters disagree. I am really conflicted whether to try it or not.

If I cover it now and harvest it a month, will it gwt any bigger? If not there isn't really much point in extending the harvest for such a small crop as I said before.

Why not try it? If it doesn't work, you might be able to figure out ways to make it work, or decide it's not worth it. If it does work, awesome. Either way you'll have your answer.

the only real reason not to try it is that he has heading lettuce. We all use leaf lettuce, which is the only true winter lettuce.

peter, I never grew head lettuce, always loose leaf. The plants by spring do not look "perfect", but you can pick middle leaves as early as snow melts. The secret is never pick when plant looks frozen, always wait for above freezing weather and then pick, better around noon, when plant adjusted to higher temps.

I guess it is worth trying. It is not all heading lettuce - there is leaf lettuce also. And carrots, which I will definitely plan to dig up first thing in the Spring.

Why not try it, If you have gone this far, go buy some 4 or 6 mil cheap plastic at the hardware store and put it over them. As small as your area is, it won't cost more than $10.

Will they get bigger? Can you accurately predict the weather? If it stays warm and sunny, then yes a little bit. Cold and grey, not very much.

Seriously, even if he is growing only heading lettuce (I know you're not, Peter, but even just say you are), what does it cost him to try? A few heads of lettuce? It's not an expensive experiment in time, effort, or money, why not? It may yield useful information or ideas for him for the future, either way. Can't hurt at this point, IMHO.

Well, it can hurt in that instead of a couple salads worth of lettuce, I dont get any. But it is worth trying I think.

Glad to hear it, it has been a warmer than usual fall/early winter hasn't it? I still have some greens and root vegetables outside that are perfectly fine. With an 8 day forecast like this, I think they will be fine for a while longer.

It has been a little warmer than usual yes, but the nights have still been pretty cold. All the wild vegetation is long dead, even the peas are damaged and have pretty much had it.

Yes, you can overwinter lettuce. But not all kinds of lettuce. In my zone 5a, I was able to successfully overwinter the cold-hardy varieties of lettuce under the small cold frame. They survived even the Arctic winters of 2013/2014 and then 2014/2015.. Lettuce will stop growing in winter when it gets really cold and dark, but then will kick-in again in March/April, so you can start harvesting leaves again in spring. But as it gets warmer, it starts to bolt.

The winter lettuce varieties that overwinter well here in Canada under the cold frame:

1. Valdor

2. Parella Green

3. Winter Density

4. Arctic King

Here is my Christmas lettuce harvest from past years:

That salad looks delish!!! I could eat it right now and it's 5:45 in the morning!!

I am just going to harvest my lettuce this month. It should have no problems making it to Christmas uncovered. It has had no problems with heavy freezes, and snow is unlikely. I know I could probably get it to the Spring but I doubt it would then proceed to make a large head. My wife eats a lot of lettuce so if we had to harvest most of it at once it would still get eaten. It has grown a little even in these shortest of days -- especially the Muir -- what an awesome lettuce!

Honestly it is the most green thing in the entire county! It looks happier than even my peas (which are kaput) and the brussels sprouts and broccoli. Do not believe the conventional wisdom that lettuce is not very hardy, or can't handle freeze/thaw.

Nice lettuce green_go