Is anyone else using a cold frame this winter?
Is anyone else in this group using a cold frame? It’s a great way to grow simple greens in the winter, using free solar energy. They require very little work to set up and not much work to maintain. We built one out of a sheet of foam insulation, cut up with a sheetrock knife, four $10 thrift window sashes, and duct tape.
But you can make a more permanent structure. Here’s one with a brick base (source – Roedale)
And another with a wooden base:
You can even use straw bales:
Notice that the first two are slanted, to take in more sun.
Our makeshift cold frame is on the south side of our house, near the chimney and where the off-white siding can reflect maximum sunlight down into it. There is a deciduous tree between it and the low-in-the-winter-sky sun’s path, but the leaves are off that tree by the time the cold frame needs the sunlight. (FYI that tree is a huge mulberry that shades the south side of the house from summer heat without blocking the solar things on the roof.)
Our cold frame is about 18 inches (45 cm) tall in the back and about 8 inches (20 cm) in the front. We typically load it up with leaf lettuces, some parsley (vitamins!), carrots and onions. The cold hardy kale and collards in the main garden don’t need a cold frame, and will get too tall for it anyhow. On especially cold nights we run an incandescent bulb out there for heat. On REALLY cold nights we also lay a cover over it.
The work comes in (a) keeping track of the temperatures every night, (b) going out there an closing it as needed, and (c) remembering to open it as needed when it gets too warm, plus (d) using the heat bulb and covers as needed.
It’s very little work for easy pickings and healthy food all winter.
We used cold frames before we got our high tunnels. We were able to eat greens through the winter even in zone 6A. They do require vigilance, you need to open them before the solar gain cooks them in the morning and close them before it gets too cool in the evening. On the colder nights we put a blanket on them to retain some heat. Great stuff!