I think it makes the most sense for these to be shared among participants in a given region.

That's why I didn't glom onto Bill's conifer report. But anyone else in the upper midwest should do so.

Took my first long 30 minute walk around today, because it's the first day in 20 days that isn't below normal!

Speaking in generalities, here are themes I'm seeing:

1) the incredible power of snow cover. My Camellia 'Yume' is considered a not-especially hardiness selected variety, some catalogs used to rate it as 8a or 7b...but it was near my driveway so while clearing snow with bucket and blade, decided to cover it as much as possible. Thank goodness I did think to do this while the snow was still a little loose and not completely icy yet. (If nothing else, it was to mechanically protect it from the snow I was going to have to later pile in that area)

There's enough melting to expose a bit of it, and it looks totally undamaged.

Contrast with a 'rated 6b' tea plant in the worst possible environment: denied some early 'wrapping' snow cover because of overhanging conifer branches, and way too tall to be completely snow covered, on a south slope w/o protection from winter morning sun that I'm always harping on as important*, but still exposed to reflected snow. It looks absolutely awful. Some of the worst camellia damage I've seen since I started growing camellias at my parent's house in 1994.

Before the snow got icy I rushed to scoop it onto some rare BLEs like the variegated Lithocarpus edulis - and wow, I'm glad I did. I have no doubt that without it, that would have been severely injured. Other than a branchlet I broke because the snow was starting to be icy, it looks just fine. Seeing how powerful even this icy snow was at protecting things, makes me a little less worried about, for example, my expanding outdoor Hedychium collection. But I'll still be worried until I see shoots!

2) the wisdom of the USDA zone system. Although I already sort of knew this, it's illustrating to compare last winter's brief dip to 2F, to this winter's prolonged and repeated excursions to 8F or so. Of course in the 1950s or whenever Wyman, Harvard & the USDA were developing the zone map system, they didn't have the ability to number crunch that we would now w/computers. A station's annual lowest recorded temp was easier to get. But I'm going to compare the 'number crunching' based system the Atlas of Woody Plants of China uses. I should dignify it by posting the actual definition, but it's something like the number of degree days below 3C. Very difficult to calculate until recently, but, especially in a climate w/China's stable winter weather is perhaps a more human relatable measure of 'how chilly a place is'. But looking at plants in that volume and their ratings versus what I know their USDA zones to be, I know it's just not a good system for subtropical and temperate woody plant hardiness. (could make more sense for truly tropical plants) It is abundantly clear now that at least w/respect to cold tolerance, a couple nights of 0F really is much worse than a winter of 20 nights of 10F - all other things being equal, of course, which they never are(!) - for most, but not all, plants on that particular edge of hardiness. So for example, my Trachycarpus was definitely looking more injured after last winter, although still, for it, not nearly as badly as some prior cold winters. (It's been fully defoliated twice since I planted it in spring 2015)

3) the power of provenance and selection. For example, one thing I'm 'tremendously chuffed' about (love that silly UK expression) is that my Taiwania looks totally undamaged. ALL of my California redwoods, even the largest, are at least showing a bit of damage, like snow line reflected light burning. Not this Taiwania which I believe was selected in the SE US for hardiness. Because I have a Taiwania from Sheffield seed - Chinese seed origin - where the one I planted out last winter died, dead as a doornail. Even though it was almost 1/4" caliper and about 2' tall...past the stage of looking like a tiny seedling. Based on how well the selected one has done, I don't believe more years would have helped the seedling. I strongly suspect it just wasn't from a stain selected for hardiness, since the Chinese don't have to do that in their own environment. (maybe some crazy guy wants to grow Taiwanias in, say, Beijing, but if so, they are keeping their hardy seed for themselves)

So, in fairness to Sheffield, I would say they are correct in offering that strain as 8 to 10 hardy

https://sheffields.com/seeds-for-sale/Taiwania/cryptomerioides///////697830/Chinese-Coffin-Tree,-Coffin-Tree,-Taiwania/Chinese-Coffin-Tree,-Coffin-Tree,-Taiwania

But it's obvious the one I got at Appeldoorn in Feb 2023 (best one shot nursery visit ever!) is easily at least 7b hardy. Time will tell how it will respond when I inevitably go below 5F, which I'm sure will happen again. Leading me to...drumroll please...

4) The mixed blessing of the most recent USDA zone map revision. It moved coastal Cecil county from having patches of 7b, to being almost entirely in 7b, and this winter seemingly proved the correctness of that. But you only had to go 15-20 miles to the north to find newly minted 7a areas, that I think might have been better if they'd stayed in 6b. Because they were dropping to around -5F if not lower, this winter, and have done so in recent winters as well. A lot of palm and subtropical plant collectors in central Florida are feeling 'burned' by the latest revision, to say the least! [Since people willfully 'misuse' or 'misinterpret' the USDA system, there's almost a case for revising how it works, period, but I won't go into that for now]

5) All I've learned about smart planting since the Polar Vortex winters of 2013-2015. But I'll follow up with this as I post more details observations in the month ahead. Big picture here is, dodged a bullet! Because of 1) correct plant siting 2) emergency measures (covering stuff w/snow) and 3) a bit of luck!

* - 6) rereading this after posting, I'm struck that the need to protect tenderish BLEs from winter morning sun was strikingly evidenced by this winter, too.