On the prairies we experience generally cold conditions for about
five months. The relative humidity is moderately high, since air at low
temperatures cannot hold much moisture. Most of the water in the hives
in winter comes from the bees themselves. My wintering technique
seems to deal with these conditions fairly well, but may involve more time
than a serious commercial beekeeper could afford.
        First, I use a year-round insulated inner cover. The cover
consists of a plywood box 16.25" wide, 20" long and 1" deep. A piece of
styrofoam is cut to fit snugly inside. The box is covered top and bottom
with .25" plywood. A rim .25" thick and .75" wide is applied both top and
bottom and a section of the rim about 2" long is cut out for an upper
entrance. The styrofoam acts as its own vapour barrier. In the winter I
use the cover with the upper entrance and in the summer I turn it over so
that the bees must use the lower entrance.
        Second, I arrange my hives in groups of 5 in a row on two rails
made of 2x8 lumber 10' long. In summer the hives are slid apart and in
winter they are slid back together. I place a 1" piece of styrofoam at
each end and hold the whole thing together with two 8' pieces of redi-rod
through plywood pressure plates at each end.
        Third, I place a 24" wide by 83" piece of styrofoam at the back of
the hive and hold it there with 6 large wedges between it and the
redi-rod. Another piece of styrofoam 19" wide by 83" long goes on the
front and is held on with wedges as well.
        Fourth, I cover the whole thing with a piece of plywood which has
a 1X6 nailed on the back to prevent wind blowing through. I hold the lid
on with some rocks; the 1X6 keeps it from sliding forward. Naturally the
entrances are to the south, and fortunately the winds here are from the
north.
        Finally, the lower entrances are shut almost completely. I leave a
.25" by .75" opening to let water drain out. The rails are arranged to
tilt the hives slightly forward. Closing the bottoms serves also to keep
mice out.
        I have had quite good success with these wintering methods over a
15 year period. Thicker styrofoam does not improve things
much. Each yard, of course, has 1,2,3 or 4 orphans in the fall. I have
been leaving these to their own devices and find that in good winters the
uninsulated ( except for the inner covers ) hives survive fairly well.
Last year we had a particularly savage winter and the uninsulated ones all
died. Henceforth I will make an effort to collect these odd ones and
insulate them.
 
 
 
 Donald Aitken
11710-129 Street
Edmonton Alberta Canada
T5M 0Y7