Of all the challenges faced by bees - and beekeepers - the topic of "overwintering" is one of the most commonly discussed. Even without our help, bees across the country manage to survive the cold winter months, which speaks to their incredible planning and resilience.
But there are also a few things we can do to help them including, in some cases, the avoidance of our own "meddling" (for example, being a tad too eager to get our hands on honey!).
At the highest level, it's straightforward.
As the cold weather arrives, bees stop foraging and hunker down for the winter. From that point forward they stay warm in the confines of the hive, throughout the winter. When the weather warms they appear and eventually start foraging again.
The aim is simply to survive the winter.
Under this simple explanation are behaviors and situations that are complex and amazing! Let's look more closely.
To achieve their success, a considerable number of factors need to align to support the bees. Virtually all of this is down to preparation with a little help often provided by the beekeeper. Here are just a few of the details of how bees survive the winter.
An early sign that your bees are preparing for winter will be the eviction of drones. These are worker bees kicking out their brothers!
They don't hold back, as illustrated in this video.
Bees have several ways to combat the cold weather. But the most effective is the winter cluster, an incredible achievement of collaboration to huddle around the queen for the entire winter to keep her warm.
To have any chance of getting through the winter, bees need honey. Lots of honey. Through the winter, the cluster will wind a path around the hive, consuming honey reserves built through the summer and fall. The positioning and availability of honey is important and many a colony has starved to death with honey in the hive, but just out of reach of the cluster.
During warmer winter days, the cluster may become a little less compact and, on days with sufficient warmth, bees may will leave the hive and stretch their wings, both figuratively and literally. This is a potential opportunity for the cluster to jump from one area of the hive to another. As the cold returns, the cluster will reform.
But if the cold days extend for a long period as is common in many areas of the country, especially in the north, this opportunity to regroup is not available to the cluster. In this situation, the cluster can survive if it can move over a path within the hive that always covers honey reserves. If the cluster is "stranded" in a part of the hive where honey runs out, it will not have the option to jump across to another area with honey, since the cluster must be maintained in the cold.
This is where beekeepers may experience the sadness of a lost colony, even though honey reserves lay undisturbed elsewhere in the hive.
The amount of honey required will differ, depending on the harshness of the winter. In warmer climates, for example in the US south, 50 lbs of honey may sustain the colony for the brief winter. However, in the north and in Canada much more honey may be needed, as much as 150 lbs in extreme conditions. That's a great deal of honey.
Wherever possible, it is better to let the bees take care of themselves. They have a natural disposition to do so, honed over millions of years. So when they kick out the drones, ease up on the production of brood and form the winter cluster, it's all part of an elaborate plan that has served them so well, for so long.
But if there are non-invasive ways to help them, then many beekeepers will consider doing just that. Let's look at some ways beekeepers can help.
It is possible to analyze and calculate and come up with many reasons you can and should take honey from your bees in their first year if they build strong reserves of honey. But a first-year colony is an unknown quantity, as is the coldness of the upcoming winter.
So we prefer a simple rule - don't take honey from your bees in their first year.
Yes, there will be many who argue that this is overly conservative and will take moderate amounts of honey, while still expecting to see their bees survive the winter. But is it worth it? Is honey so important that this is necessary, in that vital first year for the colony?
Because there are so many variables at play we like the simplicity of "no honey in year one".
Feeding is a topic unto itself. Again, a starting point for any consideration is whether there is a way for bees to take care of themselves. A good example of when it is very difficult for them is after the installation of a package of bees.
Many beekeepers feel this is one time when feeding is justified. However, it is also common for beekeepers to offer food in the fall. If your bees have been successful in building honey reserves, then hopefully this is unnecessary. But if they seem short, the weather isn't conducive to foraging or there are few blooming flowers available, then a sugar syrup mixture is often fed. Another common and effective option is to ensure fondant is available.
A popular choice of feeder is the Hive Top Feeder. This is used in a way similar to a box, namely it is installed on top of a regular box and the inner and top covers placed on top of the feeder. The reservoirs hold the sugar syrup and bees climb up the center for access. The feeder can contain 1.5 gallons of sugar syrup, which allows some time to pass before the feeder needs to be checked.
Some beekeepers store a frame or two from the summer harvest, which they then use in the fall as a way to augment what the bees have collected themselves. One advantage of this is that the source of the honey is known. Never feed honey from an unknown source, due to the possibility of it bringing damaging spores, such as American Foulbrood.
The threat of moisture can be a significant threat to bee's survival chances in the winter. This not related to rain (that's a separate topic, with implications for the cover and slanting of the hive).
Condensation within the hive is caused by warm conditions created by the cluster and the low ambient temperature. This is a perfect combination to create condensation - lots of it.
In very bad situations, the bees might be "rained on" (on a perfectly dry day) when water condenses and then falls onto the cluster.
Resolving this can be a fine balance between ensuring the hive is ventilated vs. ensuring cold air does not enter the hive.
An aid to this issue is the use of "wicking" materials, such as a burlap sack or wood shavings, which do a fine job of absorbing moisture.
The winter cluster does an amazing job of protecting the queen, including keeping her in a space that stays warm. Assuming they have sufficient honey reserves, bees can take care of themselves well, even in very low temperatures.
Perhaps the biggest challenge isn't so much the external temperature but the effect of strong winds. In the winter, a strong wind can ensure the cold air finds every nook and cranny. In positioning your beehive, you have hopefully placed it in a position protected from strong winds, regardless of the season.
Although rarely necessary other than in very cold climates, hive wrappers can be purchased, to help retain the heat.
As fall arrives, it is important to understand the situation regarding mites. Many beekeepers treat for mites at this time. Treating doesn't have to mean the application of man-made chemicals, via pesticides. Many prefer to use natural products such as those based on thymol or formic acid.
There are some challenges with these products, even though they can be very effective at treating mites. First, their application can be time-consuming and difficult. Second, it is important that no honey boxes are present, since these products would contaminate the honey.
One example of a product that is heavily used for such scenarios is Api Life VAR, which is composed of all-natural oils and applied over a three-week period.
Treatments such as these should be applied proactively and relatively early, to set up winter bees for success. This normally means treating summer bees late in the summer and into early fall. This "cleanses" the colony, hopefully in a way helpful to the winter bees that come a little later.