Did I kill my bees?

Hi there! I have two Layen's style beehives, which I built mostly by following the instructions at https://horizontalhive.com/. This was the second winter for one of the hives, and it was the first one for the other. At the end of October, I thought I was winterizing my hives by putting several layers of fabric on top of the frames including clean undershirts and towels. In one of the hives, I even put a small cushion. All of these materials were placed above the frames and underneath the lid. The lid has two side ventilations and the hive has a screened hole at the bottom to allow airflow. After collecting the honey and making sure to leave the bees a generous amount, I removed the empty frames and put an insulation board to tuck the bees in to one side of the hive (to the side where the entrance is). Finally, I reduced the size of the size of the entrance slit to prevent unnecessary heat loss.

When I arrived at the side today, I was faced with a catastrophe. All bees in both hives were dead. The fabrics in one of the hives were clearly wet. Perhaps rain found a way to get in it couldn't dry out. The top of the frames were all moldy. Even the left-over honey looked quite dark and unusable. The second hive appeared to be dry, but nonetheless the bees were all dead.

Now, a number of things could have gone wrong of course including some kind of infestation. But I was wondering if it was a mistake to use fabric as an insulation. I wonder if it got wet because of rain finding a way in or because of the condensation from within the hive. I would be very happy to hear your advice on this matter -- in particular whether I was doing something bad for the bees in an attempt to keep them warm.

As an extra information, I want to keep bees naturally by providing them good conditions and leaving generous amounts of honey for their consumption, which they make for themselves anyways. I don't want to feed sugar or spray any kind of chemicals. I am not in it for profit, but simply for the joy of keeping bees. My climate is a continental one, with relatively cold winters (can go below 0 degrees Celcius but daytime temperatures are usually around 0-10 degrees Celcius in winter).

As a related question, how can I clean the hive and the frames which got moldy? I hope I don't have to throw them away and start anew -- especially for the hive. My frames are also custom build as the hive dimensions are non-standard. Looking forward to your advice.

Oguz

With temperatures not getting much below 0C you really don't need to add any insulation. This winter my bees survived temps -25C with only insulation on top, none on the sides.
It's possible your bees needed more air circulation.
It's also possible varroa mites weakened them so much that they died.

As for cleaning the hives, it is not that important. Brush off the dead bees and scape off the wood. If you put new bees in the same hive they will clean off all the mold from the frames and wood.

Hi Oguz,

I've been keeping my bees since 20 years now, both on standard Dadant hives and in Layens hives, the latter built on schematics from the same source you used, even if slightly adapted to my specific climate.

My experience about what you ask is basically this:

1) If provided with a good amount of honey, bees are able to cope with extreme cold quite well, so I would focus more on being sure they are well packed with food than on insulating them, even if a proper insulation of the hive is clearly a good help. Sadly, thermally-insulating hives can be quite tricky, since it can easily cause moisture problems.

2) Be carefull on avoiding treating your bees against varroa. I know it would be better to avoid any chemicals, but there are also effettive organic treatments available. If you want to avoid varroa treatments you will be bound to accept heavy or even complete losses on many years. I think that the most likely cause of your losses is linked to this aspect.

I'm so sad of hearing about your bees. I hope you will have a much better season in 2026.

Have a nice afternoon,

Alessandro

It's been decades since I kept bees, but no book or beekeeper I consulted recommended such insulation. As another poster mentioned, some ventilation is necessary. Excess moisture is to be avoided. Shelter of some kind that protects them from bitterly cold wind is useful, but normal hives are weatherproof. Consider that wild bees survive winter cold without special treatment.

Ahmet Oguz Akyuz wrote:Hi there! I have two Layen's style beehives, which I built mostly by following the instructions at https://horizontalhive.com/. This was the second winter for one of the hives, and it was the first one for the other. At the end of October, I thought I was winterizing my hives by putting several layers of fabric on top of the frames including clean undershirts and towels. In one of the hives, I even put a small cushion. All of these materials were placed above the frames and underneath the lid. The lid has two side ventilations and the hive has a screened hole at the bottom to allow airflow. After collecting the honey and making sure to leave the bees a generous amount, I removed the empty frames and put an insulation board to tuck the bees in to one side of the hive (to the side where the entrance is). Finally, I reduced the size of the size of the entrance slit to prevent unnecessary heat loss.

When I arrived at the side today, I was faced with a catastrophe. All bees in both hives were dead. The fabrics in one of the hives were clearly wet. Perhaps rain found a way to get in it couldn't dry out. The top of the frames were all moldy. Even the left-over honey looked quite dark and unusable. The second hive appeared to be dry, but nonetheless the bees were all dead.

Now, a number of things could have gone wrong of course including some kind of infestation. But I was wondering if it was a mistake to use fabric as an insulation. I wonder if it got wet because of rain finding a way in or because of the condensation from within the hive. I would be very happy to hear your advice on this matter -- in particular whether I was doing something bad for the bees in an attempt to keep them warm.

As an extra information, I want to keep bees naturally by providing them good conditions and leaving generous amounts of honey for their consumption, which they make for themselves anyways. I don't want to feed sugar or spray any kind of chemicals. I am not in it for profit, but simply for the joy of keeping bees. My climate is a continental one, with relatively cold winters (can go below 0 degrees Celcius but daytime temperatures are usually around 0-10 degrees Celcius in winter).

As a related question, how can I clean the hive and the frames which got moldy? I hope I don't have to throw them away and start anew -- especially for the hive. My frames are also custom build as the hive dimensions are non-standard. Looking forward to your advice.

Oguz

The fact that you had mold shows that moisture was the culprit. You will have to figure out how that happened. In very cold weather, Layen hives may not perform as well because as heat rises, there is not as much room  for the bees to congregate. Did the workers become separated from the queen? Is pesticide pressure high near you? (I gave up trying to purchase pricey queens and equipment because although people will tell you that a queen can last 2 years, in practice around here (Central WI. zone 4b), Commercial beekeepers replace them in the fall and in the spring. We have problems with not enough drones and drones that are not virile enough, so instead of being properly mated, the queen doesn't have enough to last 2 years.
Maybe it's not a good practice to put those green frames in the hive [They have larger cells, so they accommodate drones better. The queen lays drone eggs in them and when the beekeeper wants to, he can kill all the drones in one fell swoop. Well, then, there are not enough drones in the area to mate with the queens!]
I make sure I have one hive ready to capture a swarm as well as culture that favor pollinators. Sometimes, I get lucky.
To clean your equipment, scrape it as best you can, pressure wash if you must and keep it in the sun or bake it.
We didn't use to have waxworms wintering over because it gets quite cold, but wax worm appeared in 2020 around here. They make tunnels through the wood even. For those, you may want to pick them off if possible. If not, freeze the frames. the bees will clean them up. (But it's a pity to have the bees work on that when they should be making honey). If discovered in the fall, you would have to feed them heavy!

Dear All,

Thank you very much for these valuable responses. What I conclude from these is that, bees definitely do not need as much winter protection as I thought that they would need. Staying dry and well-ventilated are the most important things.  This has become a lesson for me. In the following seasons, I think I will simply place a soft bee-fabric on top of the frames. This failure prompted me to build some swarm traps and try to capture swarms this season. This was a part of beekeeping that I had not intended to jump right in, but the circumstances make it a necessity now (buying bees is really expensive and I think their health would be inferior to a colony that has swarmed on its own -- especially if caught early in the season).

Thanks,
Oguz

Bee trapping is fun.

Hi!.

I’m planning to keep bees as part of my project. It seems to me one of the most rewarding activities and one of the best fits for the land: pollination, honey, wax, and all the life that comes with having bees around.

I’ve also been thinking about protecting the hive in winter from the outside, using insulating panels like an outer shell or box around the hive. I’m not sure whether this would actually make things more comfortable for the bees, but I suspect that reducing some of the cold exposure might lower their winter stress.

Where my land is, the cold is usually not too extreme, but temperatures can still drop to -12°C (around 10.4°F).

Juan Roble wrote:Hi!.
I’ve also been thinking about protecting the hive in winter from the outside, using insulating panels like an outer shell or box around the hive. I’m not sure whether this would actually make things more comfortable for the bees, but I suspect that reducing some of the cold exposure might lower their winter stress.
Where my land is, the cold is usually not too extreme, but temperatures can still drop to -12°C (around 10.4°F).

You are correct that reducing stress from the cold will help your bees be more comfortable. You mention "insulating panels". Be careful to maintain adequate ventilation as these panels do not let any air in or out when they are tight: even though bees do not have lungs, they do have "spiracles" through which they absorb the oxygen from the air. They also need to fly out, even in the deep of winter to "cleanse"/ get rid of feces.
I live in Central Wisconsin, and we have severe winters, with temps that can reach -40F (=-40C) exceptionally, and they do survive those winters.
More important is to make sure that they have enough "stores", that they have made enough honey, (so don't take too much for yourself). To insure the bees survive, some beekeepers let them have all their honey and do not plunder their stores until dandelions come back.
Unlike  some mammals, bees do not hibernate, in the sense of going into a torpor. They cluster around their queen to keep her warm. They eat the honey they gathered during the summer for energy, and with that energy, they shiver.

Ahmet Oguz Akyuz wrote:Hi there! I have two Layen's style beehives, which I built mostly by following the instructions at https://horizontalhive.com/. This was the second winter for one of the hives, and it was the first one for the other. At the end of October, I thought I was winterizing my hives by putting several layers of fabric on top of the frames including clean undershirts and towels. In one of the hives, I even put a small cushion. All of these materials were placed above the frames and underneath the lid. The lid has two side ventilations and the hive has a screened hole at the bottom to allow airflow. After collecting the honey and making sure to leave the bees a generous amount, I removed the empty frames and put an insulation board to tuck the bees in to one side of the hive (to the side where the entrance is). Finally, I reduced the size of the size of the entrance slit to prevent unnecessary heat loss.
Oguz

Did you insulate the hive with wool or 2" thick poly foam insulation board during the build? With wool is how the purchased hives come. Even with that, with my Layens hive, I put 3/4" thick foam board up around the sides and on top. What caused the wetness is the heat rising, concensing on the metal top, and then dropping back down on the frames area. I had an old fuzzy light weight blanket that I folded into 4 layers and laid that on the top of the frames. I always leave 10 frames of honey for the bees and install the divider board, leaving the empty frames out of the hive. This allows the bees to produce the heat needed to keep them through the winter, yet allows the larger hollow to be colder. That has kept my bees through 3 winters!

Do you know that towards the end of Fall that the Queen produces some larger, stronger bees to last through the 3 months or so of winter? Then in early Spring their eggs produce normal sized bees again? ALSO, people say NOT to feed the bees sugar water in Spring, however, I see bees flying around looking for food before trees and other growths have food available for the bees. I give the bees a boost by feeding through 2 or 3 sacks of sugar water. I use a 4 lb sack of sugar, 9 cups of water, and heated only to 120 degrees F, let cool down and then pour that into a 5 gallon bucket tilted to a 45 degree angle with winter dried stems of lilies as floats for the bees to land on and consume the sugar water. It works great! But, as I say, it only goes through 2 or 3 fills of the mixture and then it is done for the Spring.

I did lose an entire Langstroth hive this past Fall through much of my own fault. I couldn't get out enough to see what was happening due to a hip replacement. The bees left and others raided the hive - completely! SO, I'm finished with the Langstroths hives any way and will have a second Layens hive this year.

Sorry about your loss! I too lost all of my first years' bees in the Langstroth as I did not have a blanket inserted at the top to catch the moisture and my bees froze. Later years I had a blanket and no problems with that. This past year I think the whole hive just disappeared.

Good Luck this year! Happy BeeKeeping!