As I mentioned in my last post, Ye Olde Deck Farm has been keeping me busy this week. The last couple of weeks we’ve been blessed with a few mild days (thank You Jesus for the chance to get outside in January!), and the Cherry Belle radishes I planted a while ago, along with some of the cold hardy greens I started in a flat, were beginning to poke their little heads up. After assessing the options of how to proceed, it was clear it was time to finally build the cold frames I had purchased supplies for several weeks before.
I should warn you that this post isn’t going to be a step-by-step tutorial on how to assemble a cold frame. To be honest, I was too concerned with getting the things made to take the time to take photos every single step of the way. But that’s the great thing about this particular cold frame design. It’s pretty straight forward.
I want to say up front that this style of cold frame was not my idea. As I so often do when I need an idea for the Deck Farm, I turn to Pinterest or an internet search to help out. If I was going to add cold frames to the Deck Farm, they were going to have to fit a few requirements:
1. They had to be fairly cheap. Mr. Awesome and I are in a season of our lives where we need to be extra smart in our spending. If I was going to rationalize using money, it would be a whole lot easier if it wasn’t, well, very much of it.
2. It had to be something I could build myself and put together with the limited number of tools we have. Basically, if it couldn’t be easily assembled with a jig saw and a power driver, it probably wasn’t going to happen, and making precise angle cuts wasn’t going to happen either.
3. It needed to be tall enough to accommodate containers. Most cold frames sit directly on the ground the plants are planted in. Obviously containers would elevate the plants several inches, something that would need to be provided for.
4. They had to look decent. We live in a condo with condo by-laws and such, and the very sweet lady who lives next door has a couple of windows that look out directly onto our deck, so straw bales and plastic drop cloths were out of the question.
With the above requirements swirling around my subconscious, I went hunting, and praise God, came across a pin that led me to the little pitter patter blog, where the author made a cold frame out of a couple of boards, a door hinge, and two window well covers.
Window well covers?????? Of course! Why not?? They’re ready made greenhouses! Obviously I would need to use wider boards to raise them up high enough to put containers in, but that was the only real modification I could see that would be required. I added up the cost of the materials I would need and it looked like I could throw one of them together for $35 or less, a cost that my garden mania would have little trouble in rationalizing.
I went out and bought what I would need to make one cold frame, assembled it, and put it to use protecting a few plants that I started in the fall (though, as it turned out, much too late to provide a winter harvest. Yeah, I’m new to this). Since I was so pleased with how the frame was working, I used a Christmas gift to pick up what I needed to make three more frames. For each frame I used:
- Two window well covers ($7.99/ea. = $15.98)
- Two 1″ x 12″ x 6′ untreated pine boards ($6.89/each = $13.78)
- One cheap door hinge ($1.29)
- Various screws to hold everything together (mostly used what I had, but bought a box of small screws, probably less than $2)
Total cost: $33.05 + tax
Tools required to assemble the cold frame:
- Jig saw (you could really use any appropriate power saw)
- Power driver/drill
- Measuring tape
A few assembly tips:
- Write down your measurements so you will have them in the future in case you want to make extra frames.
- Building them in batches is pretty easy, so you might want to consider doing a few at a time.
- Save yourself the heartache and drill your holes before screwing the boards together to keep them from splitting. The only times I didn’t find this to be a benefit was when I was using smaller screws to attach the well covers to the tops of the frames, and when I was putting in the hinge.
- When attaching the well covers to the wooden frame, begin by doing one screw on each end first and work from there. This will make sure things stay lined up fairly well.
- Build both halves of the frame, but only attach the hinge to one side before you get the cold frame in place. Each half is pretty light weight and easy to carry around. Not so when it is fully assembled.
One of the best things about these cold frames is how easy they are to vent. With the hinge, you just swing them open as far as you want. Boom! Quick and easy! They’re also super easy to clean snow off of, which is another *BIG* bonus.
And I believe they look quite smart. I thought at first I might try to paint them, but I eventually decided against it. They will hopefully weather gracefully as time goes by.
Now, one of the biggest hurdles of having cold frames placed up off of the ground and filled with relatively small containers of soil is going to be heat retention. With a traditional cold frame, the earth provides this to keep what’s planted inside it a bit warmer and provide protection. The wood decking will do some of this, but I’m not sure how much. This is something I’m still working on and need some time to experiment with. For the first frame I made, I lined the bottom with a layer of paving bricks in hopes that they would absorb heat during the day and radiate it back at night.
There are also other options I’m considering for the future: sheets of foam insulation, rolls of reflective insulation, bottles of water, bubble wrap, etc. Adding extra heat retention is obviously most important when trying to overwinter plants in the frames. I’m not certain, but I think it will be less of an issue when using the frames to start plants in early spring. Again, it’s all experimental for me right now.
Another area I want to look into is providing a second layer of cover somehow within the frames. Eliot Coleman accomplishes this by using row covers in greenhouses, and 19th century French market gardeners used to throw mats over their cloches. Since we live in a condo, neither of these are options for us, but it seems to me that there should be a way of making a second layer within the frame either with agricultural fabric or clear plastic that will provide an extra layer of protection during really cold spells, sort of a miniaturized version of Coleman’s setup.
We did get some really low temps earlier in the season, but fortunately it snowed quite a bit before hand. I got outside and banked snow up around the sides of the one cold frame I had at the time, and covered it in a nice pile of snow as well. This seemed to work perfectly, and the plants came through the cold snap fairly ok, though I think I uncovered them too soon and they suffered for it. Either that or I didn’t air the frame on a sunny day when I should have.
I’m really pleased with these cold frames, and so thankful to have four of them now! I can’t wait to see how well they work for starting plants in the spring. If I missed anything or you have any questions, please leave a comment below. Have a blessed weekend!