North American Fruit Explorers mailing list at ibiblio

[Bernie Nikolai <BNikolai@shaw.ca>]

     Jim asked why his Honeycrisp and Zestar didn't have damage in Minnesota
when he experienced the same minimum temperatures as I do in central
Alberta.  My guess Jim is the DURATION of the cold.  Here I can get days
(literally) of a high temperature of -30F and a low temperature of -40F.
The "mean" temperature over the 24 hour period might be -36 or -37F.  I'd
suspect when you hit -40F, its for an hour at 5 AM, and the "mean"
temperature over the 24 hour period might be a balmy, near banana
elt  -22F.
     I've noticed trees and plants can take a very brief dip into very cold
temperatures and come out unscathed.  But put the plant in those same
temperatures for many hours/days, and they are finished.  Perhaps they are
like members of the Polar Bear clubs here in Canada that on Jan. 1, today,
leap into frozen lakes with holes cut out of the ice and frolic insanely
about.  They can do this for 2 or 3 minutes, but nobody seems to last for an
hour or overnight :)
   Oh, and I forgot to mention both Sweet 16 and State Fair have been
attempted at my orchard, are all gone now (about 2 trees of each 10 died
over the last 5 winters), and my perception is both are slightly LESS hardy
than either Zestar and Honeycrisp.
     By the way, I remember doing a climate study for a project way back in
high school in Winnipeg, Manitoba, and the ONLY place on the entire planet
that has a similar climate to the Canadian Prairies is termed "the Western
Siberian Plateau".   That's not exactly a heart warming thought to me...but
this winter has been awesome, and just maybe the Lapins Sweet Cherry that I
have been very tenderly nursing along in the best microclimate in my
backyard and wrapping with burlap just might make it through without damage
for the first time ever.