I'm surprised how well a double tunnel insulates plants. I thought everything would be dead by now. Especially after our record breaking -12.8 F (-25 C) night. Spinach, kale, mustard, bunching onions and cilantro are perfectly happy. (My kale outside of the tunnel is dead.) Lettuce, arugula and chard in the tunnel are cold-singed but will recover fast I think. Probably turnips and daikon radish (the large dead-ish looking plants in the center) are not good choices for a winter tunnel.
We're getting some warm days, 40s and 50s, and the sun is getting stronger and daylight is longer, so I think things will start growing soon. I haven't harvested anything in just over a month (since January 12).
