My cold frame temperature is getting up to 27*F (-3*C) or so with the midday sun on it, but it goes back down to bitter cold at night. It hasn't gotten above freezing in several days now. The greens are wilted. I have broccoli, escarole, bok choi spinach, lettuce, parsley and rosemary growing inside it. I don't know if anything will survive. It hasn't gotten this cold since we built the cold frame.
I'm having the same problem--I was lulled by two non-winters and thought I could overwinter more than I can, but we'll see how it shakes out in a few days.
ReplyDeleteThat's a pity. Is there any way to protect the cold frame from such frosts? For example insulating with a burlap or covering with something? I'm planning to build a cold frame this spring, that's why I ask.
ReplyDeleteInsulating better might help. I've been thinking about changing the sides of my frame from plastic to a more solid material - like brick or wood.
ReplyDeleteAnd, where the two top panels touch and where they meet the sides, there are thin openings that have cloth baffles. But there are still spaces here where the wind can get in. The whole unit could be made more airtight.
I was thinking that a high hoop roof with a single sheet of plastic would be more airtight.
I put a thick tarp over the frame when we have snow coming, but I take this off as soon as I can so the sunlight will warm it up. With a "cold" frame the only thing that warms it up is the sun.
I found a really nice article here on cold frames: Cold Garden Warm Kitchen, Vegetables in Winter. It suggests that putting another cold frame outside of your cold frame will help a lot.
I suppose there's a limit to how much cold even an airtight double frame can stand.
Someone suggested to me a while back that I put a soil warming cable in the frame. Of course then its not a "cold frame", but a "hot frame". I think this would have been a good idea this year.
ReplyDeleteYou might try filling some old milk jugs with water and placing them inside the frame. The sun will warm the water during the day and the water will release it's heat at night raising the temperature inside the frame a few degrees. It's not a lot of extra warmth, but it's cheap and sometimes you only need a few extra degrees to get those little guys through the cold night!
ReplyDeleteKathy,
ReplyDeleteEven if you can't harvest from these things now, you may be surprised which plants start sending out new life come spring. The leaves that are damaged may die off, but the plants may send out new growth in the spring. We didn't have quite as cold of a winter last year, but bok choy, kale, lettuce, spinach and other greens came back to life in my cold frame last spring.
The weather gets crazier and crazier. Chicago are is expecting an ice storm tomorrow and a couple days later we're going to be in the 60's. I've never had the courage to try a cold frame because of it.
ReplyDeleteI even had some below freezing temps last week down here in the desert, crazy stuff! Did have a row of mizuna freeze, but luckily I'd been too busy to plant much of anything else. Hopefully some the greens will come around for you.
ReplyDeleteOne old man told me to put a candle inside the cold frame. It may help to raise a temperature.
ReplyDeleteI bet some of them will get through it. Most are pretty hardy.
ReplyDeleteI picked some baby bok choi and the outer leaves were mush. Inner ones less mushy and maybe OK for a stir fry tonight.
ReplyDeleteI use a cold frame that I made with rigid foam insulation boards for sides/front/back, and used found glass storm windows for tops. I cover it with a blanket/tarp on very cold nights [below 15], and even when it has gone below zero this winter it has been fine, to my complete astonishment. Materials cost: around $25
ReplyDeleteI've seen some with straw bales around the sides and on top.
ReplyDelete