Source: Winter: An Update
We have not had a lot of success in keeping bees alive these past winters. We’ve had struggles with nosema, starvation, and weather beyond our control. Every year we vow to do something different, and we do, but then something else seems to kill them.
This year we were fairly aggressive in keeping the mite population in check as one of our theories was the bees were weaker than they looked going into the winter months. We also only took 2-3 frames of honey total (from our then 6 hives), so there would be plenty of honey for the winter months. Finally, we revamped our wind-block system.
In years past, we’ve seen record colds. One year there were too many cold days in a row for the bees to get out for cleansing flights. One year the well-below zero temps didn’t come until mid-February and the weak cluster just couldn’t sustain. So this year, we upgraded our plan of attack: