It might look like fall to you, with tree lines flashing flamboyant hues and pumpkin spice in the air. But if you take your cues from the stores where you shop, it could very well be Christmastime. I never mind being pushed several weeks into the future by jingle bells in the shopping aisles, or dazzling Christmas commercials on the internet. In fact, I appreciate the early, aggressive commercialism of winter holidays. It’s never too early to turn to the spiritual reflection of winter holidays! And as Richard Cushing, the Archbishop of Boston, so keenly quipped, “Plan ahead. It wasn’t raining when Noah built the ark.” In the same line of thought, a manger wasn’t Mary and Joseph’s first choice. There’s nothing wrong with thinking ahead!
The best-managed hives are ready for winter in August, and at the latest, a beekeeper should be ready for December in November (or sooner). Fall mite treatments should long be finished. Ventilation and insulation materials should be in place or close at hand. Winter feeding decisions should be made. And yet, many of us beekeepers get caught up, distracted by harvests, hayrides, and haunted walks. It’s easy to fall behind on fall beekeeping tasks. In most cases, there are ways to make up for lost time. Get comfy with a cup of hot apple cider and consider this article your catalog of the most critical late-season colony management tasks.
How do you choose the best gift to delight your colonies during the season of giving? Like any gift-giving speculation, first reflect deeply about the recipient. Who really are your bees? Over the past couple of months, they have been through a sharp existential shift. They are not the same bees you wrestled supers from in a summertime face-off. These are an entirely different population of bees, complete with a different physiological make-up. These are “winter bees,” born in September and October, with longer lifespans and larger reserves of nutrients in their fat bodies. They have to survive about 4-5 times longer than the forager forces you interacted with in summer.
While nutrition is a prime factor determining the success of overwintering, mite management is also a main factor. High levels of mites as well as high viral loads of deformed wing virus are well known to cause a colony to crash in wintertime. But even simply “being too cold,” or especially “wet and cold” can kill a colony quickly. Knowing these basics, we can create a holiday shopping and chore list well before the holiday sales and you can be first in line for Black Friday Bee Supply Sales.
Winter feeding: Load up on carbs, but hold the fruitcake — and pollen!
It goes without saying that keeping bees fed in the winter is an easier task if the hive went into winter with adequate stores. Knowing how much harder it is to get colonies through the winter in Saskatchewan than it is in Yeehaw Junction (that’s in Florida), let’s consider winter studies and information resources originating in Canada and learn what our northerly neighbors suggest about surviving wintertime.
Any first lesson in beekeeping will tell you that colonies require a specific honey weight to keep bee bellies full all winter. The Canadian Association of Professional Apiculturists published a helpful guide on regional colony overwintering with this information. Hives in Saskatchewan should have 80 to 90 pounds of stored honey, while several hours south in Wisconsin or New York state 60 to 80 pounds are recommended. Kentucky can overwinter with 55 to 60 pounds, and it is said that California colonies will get by on 30 pounds.
Care should also be given to whether or not winter stores are properly arranged. If a colony begins winter brood rearing favoring one side or corner of the hive, an extended cold spell can find bees trapped, cut off from food, leaving the cluster to starve with honey only inches away.
Consider “cluster dynamics” and the higher energetic cost of deeper cold. As temperatures drop, bees on the outside of the cluster form a close-packed “insulation layer,” wedging together more tightly to protect the warm temperature inside the cluster where bees have room to move, transfer honey stores, and feed brood. Bees maintain the inner cluster temperature at a minimum of 93 degrees F. Colder temperatures require inner-cluster bees to consume more food to generate more heat, which they do by buzzing their flight muscles. A sharp drop in temperature, then, is a double-edged sword. The cluster has to contract, shrinking in size, tightening its outer layer of bees, meanwhile still needing access to an increasing amount of food, which the cluster can only move toward very slowly.
As the brood nest expands in late-winter weeks, this double-edged sword becomes a razor’s edge, when food reserves are more depleted and temperatures fluctuate wildly. Colonies with winter brood consume twice the amount of stores than broodless ones, so help from a beekeeper before a cold snap can make a big difference. Take a quick peek under the inner cover before the polar front. Make sure the cluster hasn’t surfaced at the frame tops, (clusters always move up, not down) or hasn’t isolated itself from stores. Add a one- or two-inch spacer on top of a sheet of newspaper with a few tiny slits and pour plain, dry, granulated sugar above the brood nest — this is called “mountain camp feeding” and it’s a quick and easy way to supplement colonies short on reserves — and as an added benefit, dry sugar also absorbs moisture. Of course, candy boards are life-saving treats as well — and fast to add to a hive on a cold day, when bees need the least disturbance possible.
But is winter feeding more complex than making up for low honey weight? Shouldn’t we be ready with the perfect pollen supplement? A study from the University of Guelph in Ontario says “No” — fall and early winter pollen supplementation doesn’t give colonies any advantage. A study named “Manipulating pollen supply in honey bee colonies during the fall does not affect the performance of winter bees” compared three hive treatments:
One group of colonies was deprived of pollen (pollen traps were placed over entrances and collected pollen was taken away), another group was supplemented with pollen (pollen trapped and harvested from the first group was mixed with honey and fed to the second group over the fall), and the control group of colonies was allowed to gather and utilize pollen without interference. This study found no difference among study groups in terms of resulting spring population size, bee lifespan, colony survivability, or spring performance. This study suggested that beekeepers prioritize other seasonal management to maximize winter survival and ensure a strong spring buildup. Management suggestions were:
- Healthy hives with lower populations should be combined in the fall (that old beekeeping adage to “take your losses in the fall”).
- Pollen supplementation is more effective in the spring, when colonies can incorporate it directly into brood-rearing efforts.
A more recent study echoed these suggestions, but added something new. A study named “Can pollen supplementation mitigate the impact of nutritional stress on honey bee colonies?” pointed out that, because winter-bee brood is raised in the latest summer and earliest fall months, pollen availability is more important earlier. Trying to make up for nutritional stress in October and beyond is a wasted effort due to colony “nutritional memory.” This study further suggested that fall pollen supplementation introduced new problems like artificial brood-rearing impulses which in turn favored higher viral replications and infection levels. However, these added stresses were observed to work themselves out as winter progressed. Viral loads naturally decreased during cold months, and similarly, nosema levels naturally decreased when bees resumed spring foraging. Ultimately, this study suggested that late-season pollen supplementation is only valuable at the end of summer, when (and if) bees aren’t finding enough late-summer, early-fall pollen in their environments.
Ventilate or insulate? What’s hotter this season?
Let’s shift discussion to a winter hive byproduct of honey — water. It’s interesting to think of how two different biological functions are related in the wintertime. When bees eat honey (digestive system) and exhale moisture (respiratory system) it creates a measurable water/honey interchange. A common estimate figures one gallon of water exhaled for every 10 to 12 pounds of honey consumed. Randy Oliver breaks it down to say for each pound of honey consumed, a cup and a half of water is exhaled by the cluster. In more arid climates, condensation is a precious resource, recycled and imbibed by bees inside the hive. In temperate and wetter climates, however, this substantial amount of condensation can be a number one cluster killer, especially when it comes to severe cold, causing bees to consume more honey, and exhale more water.
For this reason, hives need a vent under the top cover “to breathe.” Position hives to conduct condensation out of the hive — water needs to drain and evaporate. It’s important to pitch hives slightly forward to allow for water drainage. Yes, I have encountered many Flow Hive beekeepers who understand the opposite, that hives should be pitched backward to help the honey drain from Flow ports. But even Flow Hives should tilt forward in the winter or water will collect on bottom boards and create dangerously damp environments. Water can be further prevented from collecting on bottom boards if it is allowed to escape from the top of the hive via evaporation. Notches or shallow shims under the inner cover act as condensation vents. Condensation that can’t escape beads under the inner cover. If it runs forward and out the front entrance, all is good. But water collecting above the cluster and showering down on bees will literally cause them to freeze. A cluster can die quickly this way.
[For more on the topic of ventilation vs. insulation, see “The Condensing Colony,” by Bill Hesbach in the February 2020 ABJ, and “Honey Bee Engineering: Top Ventilation and Top Entrances,” by Derek Mitchell in the August 2017 ABJ.]
Don’t forget the wrapping paper this holiday season! Fifteen-pound roofing paper is best! But in all seriousness, not all beekeepers need to wrap their hives. If a geographical line could be drawn to separate climates where hive wrapping is ….