ray~
"This winter I had 2-three deep hives the way U of Minn suggests"from ray's original post, the wintering method that he is speaking of, is keeping bees in 3 deeps. part of the purpose/management of the system is to ensure young queens and a healthy population of bees going into winter, with adequate honey stores, so that the need to add a spacer or any feed is unnecessary, and wintering success is increased.
from the university of minnesota:
Beekeeping in Northern Climatesthe original management of this system was developed by Dr. Basil Furgala, and is referred to as the "horizontal two-queen system". through additional research by Dr. Marla Spivak, Gary Rueter, they kept his basic management principles of building a colony and overwintering in 3 deeps, and it is not just about piling boxes on top of one another, and does require some intensive management.
in short, the goal is with a package of bees/or a divide, to be built to a strong colony with a young queen into 3 deeps the first year and for wintering.
in the spring of the 2nd year, that colony is divided, leaving the original queen ( 1 yr old, surviving the winter) in 2 deeps which is termed the 'parent colony'. this will be your honey producer. the 3rd deep, which is the divide to be queened with a young queen, will once again be allowed to build to 3 deeps that season. in late summer of the 2nd year the honey is harvested from your parent colony and is supposed to be depopulated. your divide, which should be in 3 deeps by fall will winter and the process above is repeated; it will be the parent colony, which will be divided, and the honey producer. the purpose is that these divides have young queens in them, and not over 2 years old, and the wintered colonies will a have a queen one year old.
there is a lot more to it than this, but basically young queens, strong populations, queen acceptance problems are minimized, swarming problems minimized, and honey production is enhanced. and also wintering success.
i tried this method for several years, lots of intensive management in the spring and fall. these boxes are heavy. i did not depopulate the parent colony. my success rate? it worked in good nectar years, or when i didn't experience queen problems, but like ray there was a winter or two where the bees cold starved. some keeps here keep bees in three deeps, but most do not really follow the method and will lose a percentage of their colonies. i went back to double deeps....