Cold frame reappropriation

Now that the growing season is in full swing I no longer need the cold frame to acclimatize seedlings, so have decided to conduct a little experiment involving peppers and eggplants. On the tall side of the frame (the back) I planted two peppers (of which are either jalapeno or lady bells, they weren't labled), a black eggplant, and an eggplant hybrid directly into the ground. The plants are spaced approximately 12-15" apart. Since we've had spectacular late spring weather these past few weeks I intend to keep the windows placed on top of the frame in a way such that they allow adequate ventilation but still help to transmit extra heat directly into the soil and the plants. Leaving the frame shut completely would surely spell disaster, as I would be unable to regulate the temperature at all and the plants would most likely get fried.

A picture of the newly planted peppers (left) and eggplants (right). As the plants grow I will probably have to remove the windows entirely to allow them to keep growing skyward, but for now they should reap the benefits of the additional heat that plants in the solanum family love so much.

There is a space between the windows about 8" wide and a strip along the entire front face of the frame to allow ventilation.

When a cold frame becomes a hot frame...

Yesterday was a lesson well learned regarding the heat-sinking capabilities of the cold frame. The high was 70 degrees, but inside the cold frame, it must have been much higher. High enough to scorch the few seedlings I had inside. See for yourself:


Pictured are a few luffa and birdhouse gourds that were left unattended. Until yesterday I had been removing the windows from the cold frame during the day (and returning it at night), so just such a thing wouldn't happen, but yesterday I went to my parents house in the morning and didn't return until the late afternoon. When I returned, the seedlings were wilted and bone-dry inside the sealed cold frame. I watered them and removed the windows; we'll see if any of them recover. If not I'll still have time to plant some more, as gourds prefer much hotter temps (though not as hot as they were subjected to) and a later, direct sowing might actually be beneficial over transplanting seedlings. At any rate, don't forget to be attentive to the cold frame! I'm off to the Oregon coast for a few days of camping with Jenn, hopefully my first sowed seeds will have been sprouted when I get back...

Cold framin'

Summer's still months away but it felt like it had already arrived today. Temps in the 70's and gorgeous, gorgeous sunshine. I took the opportunity to build a cold frame with some salvaged windows my dad gave me and 2x material I scrounged from the scrap pile of a construction site. There are numerous plans for building cold frames out there, but the basic construction consists of a box shape frame built with 2x boards with the windows lain on top. Here's what I was working with:

The windows are about 30"x30" and are single-pane. Double-pane would work fine as well. For this cold frame, the windows will sit side by side, so the materials required are 1 piece of 2"x12" at 60", 2 pieces of 2"x12" at 30", and a piece of 2"x8" at 60". Since I'm poor and unemployed, I screwed together 2 pieces of 2"x6" at 60" to substitute for a 2"x12" at the same length. The 2 pieces at 30" are cut so that the board tapers from a width of 11 1/4" (actual width of 2"x12") down to 9 1/8" (the actual width of the 2"x8"). This will allow rain to flow off the panes. The boards are screwed together with some three-inch screws. Four small blocks are screwed onto the inside of the frame 1 3/8" inches (the width of the panes) down from the top. The windows will sit on the blocks and be flush with the top of the frame. Here's the finished product:

A block of wood screwed to the outside of one of the windows will allow you to easily lift it off to access the inside. In my research on seedlings, I read that before planting them in the garden it is beneficial to allow them to sit outside for a few nights to adjust to cooler nighttime temps. The cold frame (if properly insulated) will keep the plants up to 5 degrees warmer than outside the frame. Later on in the season I may directly plant lettuce or other over-wintering varieties within the frame. For now it will serve to acclimatize seedlings before I plant them in their permanent dirt home.