"...as long as your average daytime temps are somewhere between oh, 65°-33°, you can go ahead and plant those seeds"
We actually
have been having some pretty mild weather this month, with our highs around 33-34F, lows in the high 20s... but before long things will take a turn for the worse (December has actually been MUCH warmer than November was) and we'll be having highs in the teens, if that (and lows well below freezing)
I definitely plan to plant the collards as early as possible in the spring, though -- if I can find the ground under the snow, that is !
If need be, I'll plant them inside this hoophouse that I set up this fall -- it's made from the frame of a HH that I bought a few years ago on Ebay, unfortunately the fitted cover that came with it self destructed in less than one year. We added some wooden framing to fasten the plastic covering to, and made a door for each end for entry and ventilation. Right now I still have some lettuce, kohlrabi, turnips, carrots, scallions and broccoli planted in there and still holding their own; the only problem I've had is slug damage to the plants -- they apparently approved of the extension of their plant-eating season!
The photo on the right was taken on Nov. 24th, when our temps were falling to about 6F at nighttime.
The big lump under the snow (to the left of the hoop trellis) in this photo is a "low tunnel" made with PVC pipe, pretty much as you describe in the tutorial -- haven't dug it out to check for a while now, but there are scallions inside. LOL, when I planted the onion sets I expected to at least get small bulbs by the time the weather got really cold... until it occurred to me that they were no doubt long-day types and our days at that point were already pretty short! Nice green onions, though
