Brian Fackler – Cornell University Master Beekeeper
In October, the days will start to be colder and the bees will not fly as much. The queen now is
laying fewer eggs and the entire colony is preparing for the cold winter months. Be sure to set
up your hive for winter before the end of the month. The decision to overwinter with moisture
control by either using ventilation or condensing both can each lead to success. Starvation and
moisture are the major factors in winter hive failure.
Mouse Guards
If you haven’t done so already, be sure to put your mouse guards on – but make sure a
mouse does not get trapped inside. During a hive inspection, look inside the entrance
with a flashlight. If you do not see mouse nesting material on the bottom board, you’re
probably okay. If you do, you need to remove it otherwise the mouse could cause severe
damage over the winter.
Feeding
A general guideline is that one colony will need approximately 60 to 70 pounds of honey
to make it through winter. Weigh or heft you hives to make a determination of honey
stores.
During the cold winter months consider winter patties, fondant and candy boards.
If you’re worried that your bees will not have enough stores going into winter, feed them
1:1 sugar syrup, which mimics the nectar flow.
2:1 sugar syrup when the weather starts getting cooler or you notice the nectar flow
tapering off.
In warm weather syrup ferments quickly and to prevent this add 1 tsp bleach per gallon of
syrup or one tablespoon each of white vinegar and lemon juice.
Avoid adding Honey-B-Healthy or ProHealth as this encourages robbing. If you do use
Honey-B-Healthy or ProHealth only use it only with an internal feeder.
In mixing 2:1 syrup boil water first and remove from heat before adding sugar as you
might scorch the sugar which possibly can form HMF (5-hydroxymethylfurfural), which is
toxic to honeybees.
Stop feeding sugar syrup when daytime temperatures are below 57 F
Preparing Hives for Winter
Wrap or close all air gaps between the supers
Reduce to winter hive size – two deep or three medium supers or less
Remove the queen excluder
Lower entrance to be reduced to a minimum size
Remove any left behind varroa mite treatment
Ventilating Hive
Involves removing the hive moisture with ventilation or capture
Vivaldi board or quilt box installed with moisture wicking materials
Upper entrance closed or open
Screen bottom board closed or open
Condensing Hive
Mimics bee biology and what bees naturally create in a tree cavity
The temperature above the bee cluster must be maintained below the dew point
Less honey is needed stored in the hive by possibly 25 to 50%
The winter lower metabolic rate is maintained by keeping CO2 in the hive
Moisture is maintained in the hive as the bees consume only water diluted honey
The concept includes: insulation between inner and outer cover, no upper entrance,
screen bottom board sample board fully inserted, wrapping and or sealing cracks and
openings
Top Bar Hives
Now is the time to start moving your bars and reorganizing them for winter.
If you have a center entrance hive, that means moving them toward the center with your
follower board on either side of the hive entrance with all stores down to one side.
Think about what you will use as a windbreak and make sure your mouse guards are on.
Varroa Mites
With temperatures getting colder, treatment options for varroa are limited.
Results of the PNW Honey Survey show that treating for varroa during the year made a
significant difference in survival rates.
Sample your colonies for varroa mites and apply treatment as needed. Honey Bee
Coalition Tools for Varroa Management is your best guidance on sampling technique and
treatment options.
Make sure you follow the recommendations precisely for the treatment you choose. Some
treatments can only be applied when honey supers are off while others need a certain
outdoor temperature. Check the extended weather forecast.
After treatment, re-sample to make sure the treatment was effective. This is very
important and should not be overlooked.
Going into winter it is critical you have your varroa mite levels and the viruses they carry
low enough or your winter bees will not survive till next spring.
At temperatures of 50 f or lower do not open your hive and consider if needed treatment
and sampling methods using oxalic acid vapor and screen board for mite sampling.
Monitoring with a screen bottom board use a treatment threshold of five mites per day or
lower.