Methods to Reduce Winter Die Offs

There are many options to protect your colonies during the Winter months. Cold temperatures, excessive moisture, and starvation are the three main reasons why some colonies die during Winter months. Some beekeepers prefer letting nature just happen, which is one choice. Personally, I believe there are methods to give our bees an edge for survival. Those of you who participate in this topic please let us know your winter conditions. I am in North Carolina, USA, So my winters are less severe than those in Vermont.
Additionally the seasons are different depending if you are above the equator or below. This topic is intended to be a learning conversation and resource for beekeepers globally.

I would be interested to know if there are any special concerns for “over-wintering” where there is no real winter(snow/below freezing days). On average our coldest lows are in the mid to low 40’s(4-8°C). The average high on the coldest days should still allow bees to fly. But there also will not be much blooming that time of year. Will bees go through more honey wintering in these conditions then normal?

Your bees willl survive on the honey and pollen stores that you leave with them.
Personally, I would recommend new beekeepers not to harvest honey the first year. Instead make a note of how many honey frames you left for them. In the Spring flow check again to see how many honey frames they did not use. It will give you a rough idea of what stores to leave them in the future.
It greatly saddens me when new beekeepers post photos of dead bees with their backsides sticking out of empty honey comb.They were trying to get the last bit of honey before they starved.
That situation can be prevented with know-how.

  1. Don’t over harvest honey supplies.
  2. Quickly check the honey stores during the winter. It can be done without completely opening the hive. Just pry open the back of the hive where the honey supers are and lift up to gauge the weight.
  3. If honey stores are depleting then feed sugar water!

Did you know that bees will sacrifice theirselves when stores get low? They fly out of the hive to die with the hope the rest of the colony will survive.

Do you have heavy rains during your winter? Is moisture in the hives an issue?

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That was more or less what I had planned thanks Gayle. I’m not in such a huge hurry to get honey that I would jeopardize the bees.

The majority of our rainfall is July-Sept(monsoon season), and Dec-March, with average being about 3/4-1" of rain per month. The more humid time of year is probably monsoon season. Through the winter months it still stays pretty dry.

Maritime climate here in the UK. The occasional winter where I live has dipped down to -15ËšC but usually it hovers around the 5/6Ëš mark. These last two winters have been very mild with the bees clustering very little. These are the conditions where most stores are used and we run the real danger of starvation in late February/March or so as the colony gets into gear.
I run open mesh floors all year and I tend to leave a shallow of unextractable honey under the brood nest at the end of the season. The bees move this up and the empty shallow then acts as a sort of baffle through the winter months. In the Spring this is always empty and is removed.
Half my hives are cedar and half poly. I ensure a lll boxes are properly insulated with extra insulation on top and as a result have never suffered from any sort of condensation over winter.
In my opinion those folk who raise their crownboards on matchsticks to reduce condensation do so at great heat loss and consequent stores consumption. Top insulation reduces condensation to negligible levels. If you have a solid floor it’s much better to raise the brood box off the floor with those same matchsticks. Simple physics.

I have started to make the quilt boxes for my Lang hives. There have been rave reviews from the beekeepers who use them. It is a way to remove moisture away from the hive without opening the top.
The directions I am following are at:

What are your thoughts? Do you see any potential flaws that I missed?

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I am in Central Ontario, Canada. We have cold and humid winters, but not as cold as in Vermont or Saskatchewan. Half my hives have top entrances, for the other half I did not make them, I made instead holes at 2/3 from the bottom of the upper box (these hives were wintered on 2 mediums, the rest were on 3 mediums). I insulate with styrene foam board on top and some kind of hive wrap, forgot it’s name, but I ended up not liking it. Anyways, when I wrapped the hives, I left the top entrances closed with a coca cola bottle cap, but the notch in the inner cover frame was still leaking heat and humidity. At the hives with entrance at 2/3, I did not open it at the time, thinking I’m going to do it later, but forgot about it. Also at these hives the styrene foam was sealed perfectly the top, no leaks. All hives had the bottom entrance and solid bottom boards. What do you think happened? The first 20 hives that were on 3 mediums and with leaks at the top wintered perfectly, no problems what so ever. The other 20 hives had a lot of moisture inside, one had even ice and the bees died all frozen. All the top frames were full in the spring with defecation, including on top of the candy boards. Lots of dead bees on the bottoms in the spring and lots of mold. 4 hives dead from these and another from the first 20, but I think I lost the queen in this hive and another one during the transportation at the end of October when I had access to my new property.

So, this are my conclusions:

  • top entrances are a must in my humid area
  • winter all hives on 3 mediums - the goal being to get them that strong
  • wrap hives 4 on a pallet, so they keep warm to each other
    or
  • build quilts to absorb moisture - in this case top entrances can be at 2/3 of the top box
  • wrap hives individually, make sure the wrapping goes all the way up, but keep the quilt holes open
  • winter weaker hives or nucs 2 in a box on 3-4 tiers

I think this following winter I will do all variants depending on the strength of the colonies and see which method works best for my area.

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Looks as if you have thought it through :+1: I build my bees up to 3 boxes of brood and 2 supers of honey/pollen. I had only one hive last winter 5 supers tall. This spring I split it into 3 hives and they are going strong. I used the Bee Cozy insulated wrap. It is like a big tube that slides over the top of the hive.
I took a photo of it on my hive but can’t find it.
Their web site is www.nodglobal.com Coming out of Winter my bees were way ahead of others in my bee club. They stayed warm enough that they could go up into the honey stores to feed. Other people lost a lot of bees because the cluster didn’t move.
To prevent moisture I kept the screened inner cover on but placed layers of newspaper on it to draw the moisture.
I like your ideas! I too try different methods according to the strength of my hives. My apiary has gone up to 5 hives now and each one is so different.

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One thing I was thinking about; In the wild bees tend to select hive locations inside of tree cavities with a specific entrance size, entrance location, cavity size, and width of tree(wall thickness). Those four factors are ideally, a South facing, bottom oriented 2.3 in²(15 cm²) opening, 40 liter cavity size, and 3-4"(7.5-10cm) wall thickness. Given those ideals, seems like you should try to duplicate those in regard to your hives in winter. Pine and Cedar(which are the most common building materials for beekeepers and bees) have an R-Value of 1.25-1.33 per inch. So achieving an R value of 4-5.3 would mimic a tree cavity. Standard boards are 3/4"(in the US) which translates to R.9-1. So it’s no wonder bees have a rough time overwintering in a standard hive with no additional insulation. It should be pretty easy to achieve these numbers with minimal insulation and effort on our part as beekeepers. A standard water heater blanket which is usually foil wrapped denim is R 6.7

I’m referencing the research from “Honeybee Democracy” in regard to ideal hive selection.

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