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!

That has to be very disheartening to loose both colonies.  I just recently attended a class and workshop with Dr Leo, he does recommend adding a wool filled canvas pillow similar to what you did with the T shirts when night time temps are below 60f.  A few observations, t shirts and wool do not react the same when wet, a t shirt with restrict all airflow when wet, so that may be all it was, compounding the moisture issues and restricting ventilation.  But I tend to wonder if one hive had a water entrance what was too much for the bees to cope with.  I am considering a roof overhang for my hives this winter as I noticed the hive I purchased from Dr Leo has some moisture and mold issues already.  I commend you on your approach to natural beekeeping as I have the same approach.  I hope you try again, as I know I will need encouragement if my colonies had died off as well.  Best of luck!

Thank you so much dear beefriends for your comments and encouragement. I wanted to make an update post on this to let you know what happened.

Well, I built two swarm traps and hung them up on two trees that are are about 100 feet apart. These were my first swarm traps and I really did not follow much of a plan. I was only careful to make the frame size equal to my hive size so that transferring the bees, if caught one, would be easy. You can see the traps temporarily placed on top of one of my hives in the first picture.  The second picture shows the trap placed on a tree.

I scraped off some of the old frames and placed them in the trap. I also dropped a few droplets of lemongrass oil.

To my surprise, one of the traps actually caught a very good swarm. In a few weeks time I transferred it to my hive. I wasn't exactly sure how to deal with this process but one evening with the help of my father-in-law, I took the hive from the tree and put the frames in the old hive. I turned the trap over and shook it to try to transfer every little bee. I was concerned that the bees could reswarm at the original trap location the next day, but it did not happen. They seem to have accepted the transfer without much hassle.

The second trap did not catch anything but something better happened. A nice sized swarm directly went into my second hive, saving the me labor of transfer.

So in the end, I managed to recover both of my hives and eat honey from them at the end of the season. A picture of delicious honey from my hives is attached.

Very recently, I collected the excess honey ensuring that I left the lion's share for them. This time, I simply placed a thin layer of bee cloth on top of the frames (actually the bee cloth was there the entire summer). After collecting the honey, I took out the empty frames and compacted the hive by placing two layers of rockwool as an insulator from the side (coated with aluminum sheeting). I left a small opening under the rockwool layer to allow bees to explore the empty portion of the hive (a trick that is suggested in the Keeping Bees with a Smile book).

So overall, I'm a happy camper at this point. If the bees can successfully overwinter this season it would be so much the better.

Ahmet, that's beautiful.
Trapping bees is so rewarding. I try every year and usually get none, but this year 3 swarms came in. Hoping for a successful winter.

What a turnaround, Oguz. Losing both colonies and then filling both hives again from swarms, one of them moving in on its own, plus honey at the end of the season. Congratulations, that update made my day.

Alessandro mentioned varroa as the most likely cause last winter, so I'm curious: are you doing any mite counts this autumn, even if you don't plan to treat? A sugar roll doesn't hurt the bees, and it would at least tell you what each colony is carrying into winter.

Full disclosure, I'm asking partly because I'm building a small beekeeping app called Smokebook. You log an inspection with a few taps, it turns a sugar roll or sticky-board count into a mite load and compares it with the guide value for that month, and each hive keeps its own curve through the year. Whether you treat stays entirely up to you. Most apps assume you treat, so I'd really value feedback from someone keeping bees the natural way, and honestly I'm not sure yet how well it fits a Layens hive. If you or anyone here would like to try it, send me a purple moosage and I'll email you a free code.

Yaniv van der Stigchel wrote:
Alessandro mentioned varroa as the most likely cause last winter, so I'm curious: are you doing any mite counts this autumn, even if you don't plan to treat? A sugar roll doesn't hurt the bees, and it would at least tell you what each colony is carrying into winter.

I can get away without treating, if I don't mind losing a lot of hives most years. I make a lot of splits and some of them are pretty good while others fail rapidly. We have harsh winters and weak colonies usually fail before spring.

If you plan to treat there are organic options, oxalic acid, and thymol, and formic acid. Many people swear by oxalic acid but it has not seemed to improve survival for me. I have not tried formic acid or thymol.

Thanks Thom, that's a really honest answer. Lots of splits and letting the weak ones go sounds like a kind of selection in itself. Over the years, have you noticed whether the colonies that make it through tend to come from the same lines? I'm curious whether you've seen your survival rate creep up as the survivors become the stock you split from.

Yaniv van der Stigchel wrote:Thanks Thom, that's a really honest answer. Lots of splits and letting the weak ones go sounds like a kind of selection in itself. Over the years, have you noticed whether the colonies that make it through tend to come from the same lines? I'm curious whether you've seen your survival rate creep up as the survivors become the stock you split from.

I have too few hives to affect the local population much at all. So my bees will always be the average of whatever my neighbors are raising. If I had to guess, probably mostly commercial bees imported from the Southern US, which is not ideal for my area. I would need some isolation, and a few hundred hives, to really have a breeding program that had any effect.

As for survival rate, no, I have not seen a trend. 3 years ago I would have said yes, I had excellent survival for several years. But the last two years have been miserable, with poor winter survival, and also very poor queen survival.

The majority of my splits for two years have failed to requeen. I almost suspect some new virus, but in fact I see no signs of disease. The individual adult bees look and act very healthy. Just, they don't make queen cells, or the few queen cells made don't result in bred queens. I am puzzled. Perhaps it's just bad luck.

4 hives right now. Simply hoping they make it through winter.

That makes sense. With a handful of hives you're really keeping your neighbours' genetics. Sorry the last two years have been so rough. Splits that look healthy but won't raise a queen must be really frustrating. Earlier in this thread Cécile mentioned drone shortages near her. Could something like that be going on, or a run of bad weather during mating flights? I hope all four of them make it to spring.

Yaniv van der Stigchel wrote:That makes sense. With a handful of hives you're really keeping your neighbours' genetics. Sorry the last two years have been so rough. Splits that look healthy but won't raise a queen must be really frustrating. Earlier in this thread Cécile mentioned drone shortages near her. Could something like that be going on, or a run of bad weather during mating flights? I hope all four of them make it to spring.

The last two years have had poor springs. Bad weather and also weird weather due to Canadian forest fires causing weak sunshine. I do wonder if that is part of the equation.

What a comeback, Oguz — both hives back from swarms, and honey on top. One habit that helps in winter without opening anything: lift the back of the hive by hand every couple of weeks. If it suddenly feels much lighter than in autumn, that is the moment to act — since you don't feed sugar, a frame of your own honey kept aside does the job on a mild day. And in a long hive like a Layens, keep an eye on where the cluster is: in a cold snap bees can starve right next to honey that is on the far side of them. Where are your hives, if I may ask? I'm in İzmir.