North American Fruit Explorers mailing list at ibiblio

["Ernest Plutko" <ernestplutko@wiktel.com>]

The air temperature now at 6:30 PM in northern Minnesota is +8 F. 
The ground temperature under 15 inches of snow is now +27.3 F.  Quite
a difference for plant survival.  I have the sending unit of a
wireless thermometer in a plastic baggie on the ground surface
covered with 15 inches of snow.  The coldest ground surface I
monitored was +18.1 F when it was -34 F a few weeks ago.  The weather
this winter hasn't been really cold and we don't have much snow.  The
winter temps have been gradually getting higher.  Hard to say if this
is a long term or short term warming.  Might be just a temporary
warming.  A blip.  The coldest I have seen it here was -48 F.  I was
told this is now 3 ft of frost in the ground.  Under the frost level
the soil is above freezing.  Any moderately hardy plant should be
able to live under the snow at ground level.  Above the snow is a
rigorous, killing environment.  When it is -40 F you often hear big
trees boom when their trunks crack.  Last year a big bur oak next to
our house cracked.  It had 140 growth rings.
Winter finally got it.