2016/17 Colorado Over-Wintering System Experiment

This experiment utilizes a complete system with the goal of providing honey bee colonies with an environment that is as close as possible to both the thermal and hygroscopic properties of a large, hollow tree given that the bees are still inside man-made Langstroth-style hive boxes.

The intent of this system is to provide a habitat in which honey bees can survive the winter because they have a consistent environment, throughout the year, in which the colony can configure the ventilation, thermal, and hygroscopic qualities themselves, with as little interruption as possible on the part of the beekeeper.  All the components – hive stand, screened-bottom-board, entrances, top feeders, ventilated inner covers, ventilated outer covers, etc. – remain consistent throughout the year so that each colony can prepare for winter through the construction of comb, propolis, and burr comb that will not be removed or significantly altered by the beekeeper.  Again, the goal is successful over-wintering from a regional climate standpoint.  Other over-wintering factors, like mite load, are not included in this experiment.

It should be stated at this point that I am not interested in harvesting honey, or propagating honey bees that would never have a chance of surviving in the wild.  My long-term goal as a beekeeper is to propagate the genetics of hardy, locally-adapted, treatment-free honey bees that could survive in the wild if they were to swarm.  This may not be attainable in my lifetime, given the challenges that honey bees face today, but this is still my long-term goal.


(Descriptions/explanations below will refer to the photo just above that description.)


The system starts with a raised, multi-hive stand.  This stand raises the hives 20 inches off the ground.  It is 8′ long.  This stand has many purposes and advantages:

1) It gets the hives up off the ground.

2) It allows space, under the open screened-bottom-boards for varroa mites that are groomed off to fall well below the hive.

3) In the summer, when the hives are separated, it allows for room between the hives to set boxes aside during a hive inspection.

4) It allows for the addition of wood shavings below the hives, inside the stand.  This has several purposes which will be explained later.


The next step in this system is screened-bottom-boards with the solid panel debris board left out all year round.  This allows for ventilation, allows for any moisture that drips down through the hive to fall through the bottom, and allows for any varroa mites that the bees groom off to fall out of the bottom of the hive.  In the winter, leaving the debris boards out does not allow too much cold air in because the hive stand, underneath the hives, gets enclosed and insulated (more on this later).


The multi-hive stand has a hinged front panel so that both the bottoms of the hives, and the inside of the hive stand can be accessed.  In this photo, the hinged front panel is open.  You can see the inner partition – at the far right inside the hive stand – that seals the hive stand as an enclosed unit underneath the four hives.  You can also see the wood shavings that have been added inside the hive stand.  The wood shavings, in conjunction with the open screened-bottom-boards, serves three purposes:

1) Any varroa mites that are groomed off fall through the screen and down into the wood shavings.  This makes it virtually impossible for the mites to crawl back up into the hive.

2) Any condensed moisture that might possibly drip inside the hive will fall out through the bottom and be absorbed by the wood shavings.

3) The wood shavings, which are about 14″ deep, serve as insulation under the hive as well as a windbreak.


This photo also shows the movable partition, inside the hive stand, that allows the area under the hives to be sealed off from the wind and insulated with the wood shavings.


The next aspect of this system is the ability to set multiple hives together, tightly, side-by-side, in order that the colonies can share warmth during the winter.  In order to do that, I designed and built these special outer covers that overlap the hive boxes on the front and back but are flush with the hive boxes on the sides.  The three vent holes have screen on the back of them.

These outer covers also ventilate and the ventilation can be controlled by opening or closing the three 5/8″ vent holes using rubber corks.  The ability of the beekeeper to control the ventilation may be unnecessary, however, as we’ll see in a moment.


Here’s a view of the bottom of one of these outer covers.  You can see that there is a 3″ diameter vent hole on the bottom that is positioned right over the oval opening in the inner covers that I use.  Warm/moist air can rise through the oval opening in the inner cover, through this 3″ hole, and out the vent hole(s) on the front of the outer cover.  This 3″ hole also has screen on the back of it (inside of the cover).


Here’s why the corks in the three 5/8″ vent holes on the front of the outer covers may be unnecessary.  This is the 3″ hole on the bottom of one of the outer covers.  You can see that the bees crawled up through the inner cover to propolise the screen on this hole (another very good reason to use screen on these holes).  This was done, of course, to control the hive ventilation.  They did this about midsummer and I imagine that they will come up and adjust this as needed.

I have spent a lot of time pondering the implications of the propolis on this screen.  It makes me wonder if we, as beekeepers, are way too invasive late in the year.  Our practices of separating boxes, removing honey, cleaning-up burr comb, repositioning frames, etc., may completely disrupt and change the specific balances of ventilation, thermal, and hygroscopic properties that the bees have so carefully created in preparation for winter.


So here is a straight-on view of the four hives, with their specially designed outer covers, and their open screened-bottom-boards, sitting tightly side-by-side on the hive stand.  The stand has also been sealed up and insulated with wood shavings under the four hives. (It is one large opening under the four hives).


The next component in this system is this style of top feeder that I purchase from Kelley Beekeeping.  They  have a covered, plastic box in them that the bees access from the bottom, inside the hive.  This prevents robbing.


Here is a view of it with the cover off.  You can see how the bees come up from underneath to access the food.  Any kind of food can be placed in these; sugar syrup, dry sugar, or pollen patties.

You can also see how I have modified these by drilling two 5/8″ holes for ventilation.  There are two identical holes at the other end.  This allows me to leave these on year-round, whether I’m using them to feed or not.  The purpose of leaving them on all year is, again, to not disrupt the work that the bees have done to control the amount of ventilation they want in the hive.


When feeding sugar syrup, this inner cap is used.  The bees crawl up the inside of the opening, and then down the outside of the cone to access the syrup.  The inner cap prevents them from drowning.


Here is a view of one of the top feeders with granulated sugar in it.  This is how I will feed the bees through the winter.  Unfortunately, none of my colonies stored enough honey to survive the winter on just their own stores.

In this case, of course, the inner cap is not needed because there is no risk of drowning.  I misted the pile of sugar with some distilled water to which I had added just a couple of drops of lemongrass oil

I’ll add here that my goal is to not have to feed sugar to the bees.  My very strong preference is that they can survive the winter on their own stores.  I never harvest honey unless all of my colonies have more than enough to survive the winter and there is still a definite surplus.

Using a modified version of the “Mountain Camp” winter feeding method of providing granulated sugar inside the hive, I was reminded that the bees need water in order process that sugar into something they can take in and ingest.  I’ve been pondering how I could actually provide water, inside the top feeder, in a way that would minimize drowning.  I’m experimenting with this:


Even after the solid top is put on the plastic top feeder box, there is still bee space for the bees to get to the water:


These plastic top feeder boxes sit right above the open frames of the top box of the hive.  So, everything is kept warm from underneath.  That fact, plus the R10 insulation on top of the hive should keep the water from freezing if the colony is strong enough to survive anyway.



13.jpgThe final component to this system is the addition 2″ thick Dow Scorboard foam insulation on the top, back, and sides.  The 2″ thick Scorboard has an R-value of 10.0, and it is completely weatherproof.

The fronts of the hives, which get direct sunlight throughout the day, are left uncovered.

The insulation is held on by bungee cords.  These bungee cords are adjustable so that they can be tightened as they stretch over time.  And, I can easily remove the top insulation panels to check the level of food in the top feeders.

If you have read this post, I hope that you will contact me in the spring of 2017 to inquire as to whether or not I thought that this system made a difference in the successful over-wintering of honey bee colonies in Colorado at 7,100′ elevation.


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