Wait a minute. I just read the other thread about how to books for four season gardening and now I'm wondering what I did wrong.

So other people are able to grow these plants in the low 20's and snow? Then why did mine all die? Is it because I used #30 Agribon instead of plastic? I considered using plastic, but wasn't sure how I'd water it so I just went with the Agribon...

Below is a link to my blog post describing exactly how I built my low tunnels - any advice is appreciated.

Here is a link that might be useful: http://grow-peace.blogspot.com/2009/10/four-season-harvest-chenilles-low.html

Don't give up on these yet. Do you have poly you can put over the Agribon? The plants need more protection. Cut back the large leaves that are heavily damaged and wait to see what comes up from the center. You aren't going to see a lot of growth right now because the days are so short. And as you said, it's very cold. When the days are a little longer and the temps warmer you might see growth from these plants. At this point you don't have anything to lose by waiting.

I'm linking to an article that might be helpful. Good luck!

Here is a link that might be useful: Season Extension With Low Tunnels

That is helpful, thanks! I have to buy some poly but I will try it, and definitely use the idea next year!

Oh, poor you. I'm zone 7 and my hoops collapsed under snow load but the plants underneath were fine. Here are 2 suggestions: in zone 6 hoop house growers use another layer of floating row cover right on the plants. Also, I moved to the heavier agribon...my best cover so far (I'm with you on the watering part) is this stuff, dio-betalon pv film. Here's the link:
http://www.groworganic.com/search.html?pCommand=DoSearch&pMode=Search&sText=dio%20betalon&sCategory=catalog
You'll notice that it's twice as costly as heavy agribon (I hate that part!) and when you get it, it looks like fairy weave. Bur it does a much better job and you can leave it on in Spring when you have warm days and cold nights.
I would clean that up in March and re-plant. You don't need soil nematodes or carrot flies. My best winter greens so far are bok choy (a.k.a. pac choi), spinach, and corn salad and miner's lettuce.

I'd reiterate what robin maine says. Don't give up on those greens. they don't look dead to me. That's just what my chard looks like at the moment but I am confident that when the weather warms up it will recover. I wouldn't cut back anything until the weather warms up. The foliage will help protect the new shoots. Leave them alone and see what happens.

It's not clear to me what I'm looking at. You say hoop house but the pic looks like a low tunnel. Which is it?

I don't think you'd be able to have plants survive under (just) a woven fabric like agribon unless you're zone 7 or warmer. Certainly not an option here in zone 5.

My poly HH with floating row cover had the most plant damage in the month of Feb. - coldest part of the year in these parts, although this season has been a bear. Plants generally not growing this far into winter, they are just hanging out waiting for warmer temps and little longer sunshine. If you plant early enough, you hit the sweet spot - plants large enough to harvest, but young enough to deal with the cold temps.

As in all things gardening - YMMV :D

The closer to the ground you get, the more warmth, plus you can heat them up by making compost. If you do it right, compost reaches 140 degrees. The piles would have to be huge,like a big 12x10, having 3 foot wide and 3 foot high compost piles surrounding your space in a box. It would give you a 6x4 space inside. Did you dig out some of the ground? You could have a sunken bed with row covers. The earth sides would have kept them warmer.

I just bought a nice book on 4 season gardening, I missed my chance this year, but have started planting my spring garden early in zone 7.

sfallen - I thought hoop houses and low tunnels were the same thing. I guess mine must be low tunnels.

The good news is, as of this past Sunday, the mache was all back to life. I guess they were just damaged in the above picture - but now they look healthy and green and are growing some new leaves.

The turnips and carrots in my other bed also survived. The carrots weren't really edible (I don't think) since they were covered in long white hairy roots, but that's ok b/c I picked most of them in January and just left a couple in as a test. The turnip greens I left in looked great.

I cleaned up everything else, and prepped the beds for their new spring crop. I'm planning on planting new lettuce, carrot & turnip seeds this week and replacing the covers so they can get an early start. (I'm switching beds too to rotate the crops)

Next winter I am looking forward to trying again with the agribon + an extra layer of greenhouse poly.