We know that winter is the selector of great stock. Colonies whose genetics and preparations are strong will survive, while those weaker or less productive colonies will die. That being said, there are many things we, as beekeepers, can do to set the colonies up for success. Below is a list of things that we do in our yards to maintain successful colonies over winter:
Caution: If you are a beekeeper, your opinions may differ, and probably will!
This blog contains the steps we take to get our colonies though winter. There are many other options. Some may do more, others may do less. The over-wintering argument is one of those topics that really spells out the "art" of beekeeping over the science. For every beeekeeper you find who swears by doing one winter prep task, you'll find 2 more who swear against it. Utilize this information to draw your own conclusions and decisions.
Why bees die over winter
Winter losses are a multifactorial reality for beekeepers, especially those who endure some form of winter months (beekeepers in Florida, move on). In our experience: Many of the losses we see during spring deadout cleanings appear to be from the following (in order):
Lack of food stores
Crummy Genetics/ Mites
Struck by asteroid
If you just chuckled, good.. if not... call me. More on the reason cold is at the bottom of the list later on.
Lack of food stores
Very often when called to do dead-out cleanings and colony autopsies, we find many colonies without any food stores at all. Many times, bees in colonies who lack the food needed to survive winter are found dead with their butts hanging out of their cells, sadly appearing to be reaching for the last speck of food before succumbing to hunger.
Winter prep starts in September. I say that assuming global warming doesn't have us on the beaches in December, but generally, food store assessments and 2:1 feedings start in late September in our yards. Before feeding, we always assess the stores the bees currently have. In our yards, we rarely remove all of the honey from our hives, so many do go into the winter-prep stages of the season with some honey still in the supers. This is important because you want to try and get your bees to have around 60lbs of food stores for winter. 60lbs of food is generally 2 mediums or 1 deep box of honey and pollen. If you choose to feed heavy too early, remember that honey-bounding is a real thing and resources stored in the brood ness stresses the colony and the queen out as they being to feel as if space is limited.
This is one of the big killers of colonies: Moisture. Much like humans, bees don't entirely hate being cold. But being wet and cold... that's uncomfortable (and for the bees, deadly). It may be a response of initial instinct on the part of the beekeeper to want to snug the hive up as tight as possible, but airflow is as important during winter as it is in summer. The center of the colony will continue to generate heat around 93 degrees Fahrenheit all winter long. This hot air needs a way to escape, since it creates moisture once the hot air hits a cold surface like the interior walls and ceilings of the hive (more on that later). To combat moisture, we'll need to find a way to keep airflow coming and going through the hive, and ensure that those openings don't get clogged by snowfall, dead bees, or duct tape.
Crummy Genetics and Mite loads
Some colonies are predisposed to fail... you know the ones, you just won't admit it. I am certainly not in the position to be doing genetic testings on dead bees to confirm my suspicions, but in the absence of other causes, the beekeeper's recollection after finding their colony dead often paints a picture of a colony that "was always struggling" or "never seem to get its populations up." These are hits of what is to come. If you havn't heard it by now, always take your losses in the fall. Combine weak colonies in the fall instead of finding them dead and infested with opportunistic moths and beetles in the spring.
Mite loads also cause issues over winter. Simply put, diseased and weakend bees don't survive winter. It is important to have healthy winter bees, which means you're gonna need healthy nurse bees taking care of those winter bees. This underscores the importance of late summer/ early fall mite checks and treatments.
I'd be remised here if I didn't point out the importance of queen quality. Sourcing local queens is paramount, especially from breeders with good success rates and strong documentation on genetic lineage. Any queen you can graft from strong colonies will be 100x better than the majority of purchased queens out there, so when the time feels right, look up ways to promote your apiary's sustainability by grafting your own queens.
Asteroids and Assumptions
So the subtle hint at the top of the blog that bees die of cold in this part of the country is an important fallacy to understand. Bees are able to maintain heat, as long as your colony is large enough. That doesn't mean huge... it means large enough. Large enough to generate enough heat to heat their home, and large enough to withstand the acceptable losses that will occur during winter.
Bees in a cluster keep warm just like penguins. I like this analogy, though as a beekeeper I am perplexed why the general public knows more about the thermodynamics of a flightless bird from another continent than they do about one of the most important insects on the planet, but I digress. As the bees on the outside get cold, they move into the center for warmth. This cluster must be able to move freely throughout the hive (sans queen excluders), and generate enough heat to heat the internal area of the hive. That being said, it important to keep the colony in enough boxes that they can store their needed food without working their stingers off to keep it warm.
Winters in Virginia
Winters in Virginia can be hard on bees. They're hard on bees in different ways then the winters up north; which sling subzero temps over several months. I've always subscribed to the old adage that if you don't like the weather in Virginia, just wait a minute. The effects of global warming can be seen in the bees. We have had 60 degree days in december, and 40 degree highs in March. This unstable shifting of what is normal stresses the bees. The smaller the colony, the weaker their ability will be to manage the drastic fluxes of temps. last year's warm february sent bees into an elevated metabolism earlier than normal, chewing up their food stores at an alarming rate. As Virginia beekeepers, we must have a way to intervene with emergency food stores, and plan for these interruptions of what is normal.
Winter Hive Prep
Taking all these things into account, we need to be able to manage moisture and humidity, provide emergency food and a way to intervene when things get all weather-weird, and allow for unobstructed entrances clear of snow and.... "beekeepery." With that in mind, here is what we do at our bee yards, from bottom to top.
Screened Bottom Boards
Oh no! He's talking about screened vs. solid bottom boards. That's right, I used screened boards. Why? because again, the bees are able to manage our somewhat mild winters without issue. We also know that small hive beetles overwinter with the colony. Any attempt to get the to fall out onto the cold ground is welcomed in my yard. It also provides more areas for airflow, which we KNOW is important.
The "Entrance, Egress, and Guard" (EEG) Attachment by Blue Green Horizons
I completely stole this idea from the guys over at Blue Green Horizons. If you don't follow them, you should. There have some amazing examples of beekeeper ingenuity. I had made a few "front porch" style entrances after seeing how snow would build up on the landing board, but none were as simple, cheap, or versatile.
Per BGH's Facebook post, Your cut list consists of:
1 Piece - 2 1/2" X 3/4" X 15" 1 Piece - 2 1/2" X 3/4" X 12" (adjust for 8 frame)
Cut the 12" in half (we like to offset to one side) on a 45 or 60 degree angle.
Attach the sections together overlapping 1 1/4".
Before These entrances, we use to take our entrance reducers and flip them upside down, with the theory that if dead bees fell near the entrance the other girls could climb over them and still get out. I don’t know if this theory was ever proven. I never did have a colony found dead with a clogged entry way, however.
It is noted in the comments for BGH that this entrance is not really designed to be a mouse guard. If you have a mouse problem around your hives
A Slatted Rack
This was the first year I placed slatted racks on my colonies and I really like them. When I inspect the colonies, I see a lot of bees keeping cool below the racks. The amount of bearding on hot days are much lower than the colonies without racks, and over winter, it creates a barrier between the cold air near the entrance and the center of the cluster. These can be left on year long but have great benefit over winter
A Feeding Shim
Last year we had our best success rates, even with the weird warm/cold back-and-forth. The only thing I did different was adding feeding shims of fondant. When I checked the shims towards the end of real winter (you know, the one before fake-second winter) and most were almost empty. This gave me the opportunity to throw in some new fondant/pollen bricks and keep my girls fed. I subscribe to this recipe I found from Stan over at Texas Friendly Beekeeper's Facebook Page.
They are simple to make, easy to store, and work great. The bees love them. Just make sure to make your shim the same height of the pan you're making your sugar bricks out of (or visa versa).
A Vivaldi (aka quilt) Box
Quilt boxes are boxes placed on colonies to act as a wick, sucking and absorbing moisture put off by the condensation in the colony. Quilting material is usually burlap or wood chips. When I use wood chips, I usually place them in a mesh bag (like a laundry bag from the dollar store), to make switching them out easier as they get damp.
A quilt box is also a bit controversial. Many beekeepers feel like placing material inside the hive that will soak up moisture ends up doing more harm by keeping the moisture inside the hive rather than venting it out. While I agree with that theory, I have found my quilted hives to be very successful. To the consenting view’s point, if your setup and winter lifestyle doesn’t allow you to occasionally go check the quilts for moisture, then their theory stands true. That being said, I have found winters here provide enough sporadic warm-ish days to go in and make sure the quilts are dry.
A slightly more upgraded version of a quilt box is called a Vivaldi box. These are typically commercially made boxes that consist of a notched inner cover attached to a vented shim. The inner box serves as a place to provide some emergency solid food sources like sugar bricks or pollen patties. I actually use these boxes year-round, as they act as an attic in the summer, allowing hot air to escape and get off the brood nest, just remove the quilting material.
Vivaldi boxes use to be commercially available, but for whatever reason can sometimes be hard to find. Because of this, I typically make my own. The basis for the build can be found here on Vino Farms’ YouTube channel (if you don’t follow him, you should). I build mine using an already available medium super and an inner cover. No need to nail them together, I like having equipment that serves multiple purposes. To make it work, place vents like these in the super. Make sure the vents have a screen as part of their design as to not be an entry point for pests. Like other winter items I use these ”vented” supers year-round without any issue... no need to buy or store more equipment.
For the inner screen, I don’t get as fancy as the commercial setups. A little piece of political sign with some hardware cloth or screening material works just fine. Since i use the candy board, I don’t need the option to feed solid food since I can do that in the shim.
Foam Insulation Insert for Telescoping Cover
If you had to only do one thing, do this. As previously stated, hot air condensates on cold surfaces to form moisture. The coldest surface on the colony tends to be the outer cover, especially when it’s holding up a pile of snow. Using 2” foam insulation panels greatly reduces this from happening. If you choose to use a 2” piece of foam, just keep in mind that the outer cover will no longer “telescope” because the inner area of the cover is also 2.” if you choose to use the quilt box, a 1-1.5” piece of foam should work fine.
Pro Tip, always cut or shave a corner of your insulation panel to get it out easier when spring comes.
Lastly, there are two extras for the beekeeper who has it all but still wants to open a few gifts over the holidays. Infrared cameras provide an invaluable amount of data on both internal temperature and cluster positioning. Clusters tend to move up as they consume food, since they move closer to warm air and food stores and further away from the cold air of the entrance. There are both standalone FLIR cameras as well as ones that can attach to your cell phone. Do your research on these products, often you get what you pay for.
Internal temperature and humidity monitors can also tell us a lot about what’s going on inside the hive. There are a handful of manufactures out there. I happen to use the BroodMinder system with good results. Humidity monitoring through these systems can help guide when assessments of your quilting material are needed.
Hopefully these things can help lead you towards success. Do your research and learn from your mistakes. Winter success can be very regional, even in the same state. If you want to nerd out more on the winter dynamics of honeybee colonies, check out Randy Oliver's full resource page here.