Damned cold day

It's a clear, sunny day and the air temperature has soared from 0 to 5, but that's on the Fahrenheit scale, so for the rest of the educated world our high temp today is -15 C. That's cold! It was a great weather sequence, starting Friday evening with freezing rain, so Saturday starts out ice-coated and it's one of those you can barely see it coatings of ice. TPP slipped down his own front steps, while being terribly careful because it was obviously slippery, and the newspaper was out there somewhere, but it was slippery-er than was imagined, and fortunately no physical damage was done beyond slightly spraining a thumb. Then riding in on a blast of Arctic air a layer of snow was deposited on the ice. Actually at this low a temperature, it's way less slippery now than 24 hrs ago.  Tonight may well be our coldest temperature of the calendar year, and the '16-'17 winter season; the temperature is expected to be 3 to 4 degrees below zero F (-20 C).  
Plant-wise this is close to the hardiness limits for a number of plants so come spring, TPP expects some die back.  For example, one species of beauty berry is less hardy than the other and Callicarpa  bodinieri may well die back to the ground level.  Last time it took it two years to recover and flower again (this year), so the clock will get turned back again.  TPP worries about his big leafed Asch magnolia, endemic to the Florida panhandle.  It survived 0 F last year without damage but 3 to 4 degrees colder pushes the  envelop a bit further, so to help out it was heavily mulched and the bit of snow will also help. The Sinocalycanthus is also a worry at these temperatures.  This is no where near how cold it could get here, and twice in the past 40 years the low temperature has hit -19 F.  The neighbors have a very tough mimosa tree, and it may well die back and come spring they'll just have to wait and see where it sprouts, and then prune back accordingly.  
Yesterday was spent in part making currant-cherry-berry jelly, outstanding taste and bright red. Currants tend to ripen when it's too busy to make jelly, but they are easily frozen and then wait patiently for our attention. These are from the 2015 season. 2016s are waiting. 
Today will be a soup-making day - parsnip, sausage, and lentil will be a good choice. 

Cold and plant hardiness

It's been cold, seriously cold, and while restating the obvious, it perhaps prompted a reader to ask about the effect of extreme wind chills upon plants.  OK, this is an easy one; wind chill doesn't affect plants.  Only the absolute temperature matters, not how the wind makes the cold feel to us and other animals. Recently our absolute temperature hit -17 F (-27 C), and this is very near the rock bottom hardiness for zone 5 plants. In TPP's 35 years here in northern Lincolnland, the coldest it has been is -19 F. This is the absolute limit for freezing-avoiders, a topic discussed before. Until spring you really don't know what damage has been done to what plants.  Some tender woody plants will die back, and many will sprout from the base, so be patient before cutting things back.  Our Vitex (chaste tree) will certainly be in this category.  Over the past couple of years all of it survived the winters and it had gotten 2.5+ m tall.  My Mother, a native southerner, had a pet mimosa tree in upstate New York that survived because it was planted where the ample snow fall always drifted providing it with insulation.  Granted the mimosa never grew much taller than 4 feet, but she like it anyways and in bloom it often stopped traffic.  So snow cover makes a big difference, as does mulching.  This year the deep cold came with snow, so low growing things and herbaceous perennials will probably be largely undamaged.  In a few cases TPP is worried because either he or the nurserymen were cheating by planting marginally hardy plants (TPP) or over stating the hardiness of some plants (a lot of plants labelled zone 5 on nursery tags are not so rated anywhere else).  OK, so you gamble.  But it will be another 4 months before the data can be collected about what was damaged and what was not.  Another problem associated with this is that winter kill is more often about dehydration, especially of evergreens, both conifers and other types, than it is about cold.  If you stopped watering newly planted evergreens when the weather got cooler, and drier, then you put them at risk.  Again, mulching helps greatly.  Now stay tuned because next TPP will explain about frost cracks in trees and why it happens and why it doesn't.