Well, it was zero degrees according to WeatherBug when we woke up this morning - that's 0 F, about -17 C - which is nothing compared to some other places in the country over the last couple of days, but pretty darn cold for central Maryland. According to the USDA Plant Hardiness Map, we're in zone 7a (revised from 6b a couple of years ago), and 0 to 5 is our Average Annual Extreme Minimum Temperature, which is by way of saying "it hardly ever gets this cold, but we're not going to say it's out of the ordinary." It feels extraordinary nonetheless. At least the wind has stopped (probably about -15 wind chill overnight).
A lot of people around here, including me, have made attempts to grow plants that stretch the climate zones a bit, and whatever's survived all the extremes so far may get clobbered this time. I didn't bother trying to wrap up what's left of baby Celeste fig tree #2, because it already looked like in September like it wasn't going to make it. I have a gift fig growing beautifully in a pot inside, which I'll plant out this spring and coddle and wrap in the fall, but it's a less hardy variety so may not make it through another winter like this. Of course, we may not have a winter like this; we may have the non-winter of a couple of years back.
I do think this may do for what was left of the pomegranate. And I suspect my carefully-covered cardoons in the demo garden are toast.
It's always hard to lose plants, especially ones you've taken care of over many years or grown from seedlings, but this is the nature of gardening. That doesn't mean we shouldn't take chances. Climate change is real (and weather like this is why I tend to say "climate change" rather than "global warming," although global warming is real too, and is a direct cause of extreme cold events), and gardening is going to get chancier as time goes on, which I think is all to the good - Henry Mitchell was right; gardeners are defiant. I spend half my time telling people to choose climate-appropriate varieties of things, and half telling them to challenge boundaries and try something wild and new, and those aren't incompatible aims. Just don't plant your entire yard in tropical plants (unless you want to).