Just a note to clarify an earlier thread. Yes, you would expect these extreme cold spells as a result of global warming.
Global warming is not a misnomer--the earth really is heating up overall. But it can be a misleading term since the result is not noticeable warmth overall. (The most significant temperature aspect is warmer night lows, and some regions will experience overall cooling.) The prime indicator of global warming is temperature extremes and sudden fluctuations and more severe weather more often, hence the other and perhaps more useful term for global warming, "climate change."
I believe Nafexers can be very significant in addressing climate change (fruit trees being the most touchy crop becaue they take a long time to grow--they are"stuck" as a crop, unlike say cabbage). We can learn about it, work to prevent it in asmuch as humans, particularly Americans, are its cause, and experiment with new tress in new areas and with tress that can take weather extremes. (For this reason I have planted jujubes and also some varieties outside my current zone recommendations. I also vote in ways that appear obviously more likely to be constructive than others and try to share information.) The David Suzuki website ifrom Canada s helpful for deeper understanding and action suggestions.
I very much appreciate reading the careful regional observations of Doreen and others.
Jolon at Last Farm
USDA Zone 8/9