most difficult time for bees, even more so if the bee keeper hasn't
prepared the hives correctly. This is the time of year when the most
losses occur, mainly through ignorance or bad management the hives are
left to their own devices. Often the keeper has stolen the bees winter
stores, left them unprotected from the elements, then wonders why the
hive is dead come spring. Good wintering techniques start months before
the first frost.
Let us first consider the reasons why a hive fails in winter. Starvation, poor or failing queens, wet hives, disease or dwindling.
There is a misconception that honey can be taken from a hive without causing problems.
False, bees need, subject to the area they're kept in, approx 100-140 lbs of stores. Simple math, at 7 lbs per frame tells you how much stores your bees will need. Further South obviously will need less as spring comes earlier. The results of keeping your bees short of winter stores will be obvious in a slow spring build up. See feeding
It is obvious when pointed out that a failing or old queen won't make it through a hard winter, but time after time I find failed queens when analysing others failures. A queen in her second full season has a 50-50 chance of failing over the winter. So my advise, fall re-queen. A young, strong queen entering the winter has a far better chance of heading a strong hive in the early spring, leading to bigger crops. An old queen in the winter will certainly not improve before the spring.
I find it remarkable how many fail to ventilate the hive in the wettest time of the year. Warm air condenses on cold surfaces and forms ice, this then melts in the spring and often drips back into the cluster, a simple top entrance would help. That same top entrance will also prevent suffocation in the event of ice build up on the entrance reducer.
For a more definitive discussion on ventilation see Mod Kit details
Disease and Dwindling.
Without a proper fall examination for disease a hive with any of the hive diseases, Varroa, Tracheal mites, Foul brood, Chalk brood, the list seems endless, is bound to fail. A hive seems to need a 'critical mass' to be successful. So if the hive is small because of queen problems a better solution might be a unite after culling the worst queen. One strong hive is better than two weak ones, and can always be split come the next year, where two weak ones can fail, leading to no bees.
For many years I have advocated using stock bred for use in an area climatically similar to where they are to be hived. There is no point in expecting semi-tropical bees to survive in near Arctic conditions, it is unlikely to happen. It was brought home to me recently that my hypothesis is correct with an e-mail from a customer in Alaska, who managed to winter bees for the first time ever using queens provided by us.
We take great care to eliminate all of the above problems then we do the following:-
Wrap the hive,
We use black tar paper. This keeps the hive dry, and stops the snow from wetting the hive sides, it also warms the hive interior on bright sunny days allowing the bees to break cluster and move to stores. A few well placed B=" staples do a good job of holding it in place.
Always, dead bees will sometimes clog a lower entrance as house bees don't fly during the winter. Plus of course it does allow dampness to leave the hive from the top. Cold does not kill bees, wetness does.
Is really not necessary, trying to keep heat in with a top entrance is futile. Where we add insulation is over the inner cover to stop drafts upwards through the center vent holes. Add 1B= inches of blue styrene (water resistant) to the inner cover on wrapping, this is far superior to moisture absorbing newspapers, straw or wood shavings.
Keep the hive dry is a good adage.
We hear of keepers who insulate the whole hive with styrene or fibre glass wraps. My view is that when the internal hive temp drops it will be very difficult to warm it up again as its insulated from the outside warmth, whereas black tar paper absorbs the heat from the sun on clear days and transmits it to the hive interior allowing the bees to move to access food.
It is now 19 years since we completed our tests on our system and to date we haven't lost a hive to winter loss, yet. I hate to brag, but I have to believe that finally we have a system that works.
Update Approximately 4 years ago I was off work sick and failed to completely wrap one yard. It had 16 hives, all of which were readied for winter in the usual fashion, ie. 3 boxes, lots of stores, young queens etc, the only difference between them was that 8 were left unwrapped. Once I was fit again I walked around the yard, deep in snow, the results were quite remarkable. It was a bright sunny day, warm out of the wind but the air temperature was still well below freezing point. The wrapped hives had bees at the top entrance and house cleaning was taking place around the bottom entrance, whereas the unwrapped looked dead and only the faint hum said they were still alive.
The real advantage was seen when we started working the hives. The wrapped hives took down their early feed much faster, and I commented at the time that they appeared to have more brood, as the rate of feed taken is a good indicator of brood feeding. When the weather warmed enough for us to start spring management the differences were really noticeable. The wrapped hives were far in advance of the unwrapped. They had more brood, were more frugal with the winter stores, had more adult bees, bottom boards were much cleaner, and generally the hives were better placed and ready for spring.
The cost of wrapping the hive in black tar paper is approximately $1.50 per hive, not much to avoid the death of a hive. Cost of replacing that hive, over $300, by the time you add the loss of that year's honey crop, replacement and the time and effort cleaning and repairing the hive and frames.