Winterizing Honey Bees
Weather here in Minnesota was unusually cold for the end of October and beginning of November with temps at night being down in the teens. But we reached an unusual high of 61 degrees yesterday in Northfield and the remaining part of the week looks like it will be in the 40’s and 50’s.
So now is the time to get out there and winterize your bee hives if you haven’t done so already! Here are some practical tips for consideration as we prepare for the long winter months.
Practical Recommendations for Overwintering Bees
1) Honey Bee Health: It’s important to acknowledge that all of the work and effort you put into managing your hives during the fall is going to pay off during the winter. Varroa mite checks and treatment, Nosema, foul brood and chalk brood checks, as well as queen vitality, brood nest size and drone culling are all vitally important management points to make sure you have a healthy colony going into winter. You should leave 75-95lbs of honey with each overwintering hive. Unfortunately, if you haven’t assessed these things up until now, late November is not the time to start as most treatments need to be done during warmer weather with an open hive.
2) Winter Nutrition: Nutrition plays a large role in how bee colonies respond to environmental conditions. Its important to allow them to go through natural physiologic cycles as day length decreases. Do not provide overwintering bees with pollen paddies, as this will encourage them to start brood rearing and use up valuable resources. Don’t be confused by many migratory bee keeps who move bees to warmer locations during the winter and want them to have productive brood during the fall. If you have determined your colony is weak or doesn’t have enough honey stores for the winter, sugar feeding is still appropriate late into fall/early winter.
3) Choosing a place to overwinter hives: Finding a good yard to overwinter hives can be important to their survival. You want to choose a place that is sheltered from the wind, but gets a fair amount of winter sun. It should be close enough for you to be able to check the bees regularly even if there is deep snow. It’s ideal to reduce vegetation and weeds around the hives to discourage varmints from moving into the area.
4) Wrapping Your Beehive: In really cold regions like Minnesota its beneficial to wrap your bee hive. There are quite a few suggested strategies for this and one point to always consider; there must be enough ventilation to reduce moisture build up.
Hives can be wrapped using a belt-wrap method where the supers are wrapped around and around until everything is covered. Then the material is staple to the hive. Don’t forget to open holes in the wrap over your ventilation hive holes. They can also be wrapped by a sleeve method, where the material is pre-measured, sewn or stabled together, then dressed over the top of the hive. A third method is to blanket multiple hives that are right next to each other with material, then staple it in place. Good materials to wrap a hive with include:
a. Waxed black cardboard commercial winter cartons
b. Black tar paper
c. Reflectix TM
d. Six-mil black plastic
Hives wrapped by belt method. (Photo credit Manitoba Beekeeping http://mbbeekeeping.com/)
5) Ventilation: Bees are living organisms and because they warm the hive throughout the winter they produce a lot of water. The hive should have an entrance hole in the bottom, as well as a ventilation hole in the top super right below the handle. Make sure that the hive wrap you have placed has a hole in it to allow ventilation.
Ventilation hole. (Photo credit to UMN Bee Lab)
6)Moisture Boards: These are important to control moisture build-up in the colony. They are placed inside the inner cover and should be made of a porous material that collects moist ure. Sheet insulation is not a good idea because it doesn’t absorb moisture and can cause water to drip onto the cluster. Good materials to make moisture boards include:
a. 3/4” Bild Rite® sheeting
b. Shag carpet
c. 1’’ stack of newspaper
Here is an example of a moisture board. (Photo credit to UMN Bee Lab)
Those are at least the basics of tending overwintering honey bees. For now I’m going to head outside and try to enjoy some of this last minute warm weather. Although secretly I’m hoping for lots snow so cross country skiing can get underway!!
As always, thanks for reading and enjoy.
Eva Reinicke DVM
Doke, M. A., Frazier, Maryann, Grozinger, Christina M. Overwintering honey bees: biology and management. Current Opinion in Insect Science. 2015, 10:185-193
Reuter, Gary S., Spivak, Marla. Wrapping Honey Bee Colony for a Northern Winter. University of Minnesota Instructional Poster #163.1, Department of Entomology.
Watson, Eliese. Winterization Guide for Beekeeping. Apiaries and Bees for Communities. http://www.backyardbees.ca