Winterizing Beehives Successfully

​Winter is just around the corner and the coldest days are still ahead… brr !

I don’t do cold very well. I always have to put on multiple layers of clothes just to keep warm. Winter is also a strain for bees, especially if you live in a cool northern region. You may be wondering how to prepare your beehives for the cold months ahead? Getting honey bees from late fall to spring in good condition requires a bit of help. So what can you do to winterize your beehives with success? The following should be on your checklist for winter preparation:

• ​Protect the Entrance of the Hive
• ​Set up Feeding for  Winter
• ​Ventilating hives in the Winter
• ​Remove the Queen Excluder
• ​Insulating Beehives for Winter
• ​Keep your Hives Dry
• ​Shelter them from the Wind
• ​General Hive Maintenance

​Overwintering honey bees actually begins in late summer or early fall. It’s part of a beekeepers month to month practices to prepare a colony for the upcoming winter period. But after you make your final inspection of the season you’ll need to setup a winter hive configuration.The following guide should help you install your hive for the wintery months.

Protect the Entrance of the Hive

Winter hive preparation begins in the late fall around October (assuming you live in the northern hemisphere). One of the first things most beekeepers do at this time of year is fit a mouse guard to the entrance of the hive.

When the weather is good, bees can normally defend themselves against intruders. But in winter it’s too cold. The bees are busy keeping the queen bee warm and cannot guard the hive entrance all the time. Mice are on the lookout for free food and a warm place to stay, so beekeepers give their colonies a helping hand by attaching a mouse guard.

This takes the form of a metal grill with holes of about ⅓ of an inch (9mm). This is enough to let the bees in and out, but too small for a mouse to get through.

Try to judge the right moment for fixing the mouse guard. If the colony is still very active, the guard can be an obstacle for bees who are cleaning the hive and removing dead bees for example. Bees should start to cluster inside the hive when the temperature drops to around 10°C/50°F.

You can also keep the entrance free from snow by installing a entrance snow visor. These are particularly useful if you can’t reach your hives often during winter and you live in a snowy climate. You may not need this if your beehives are in your backyard and are easy to check.

Some people choose to use an entrance reducer during winter to discourage mice and also reduce drafts. An entrance reducer is basically a piece of wood which is placed in front of the entry to lessen the size of the entrance. They have two different sized entrance holes.  

I’ve heard that you need to be careful about using a hive reducer in winter. Older bees tend to die off naturally at this time of the year and you can get an accumulation of bee bodies near the entrance. If a lot of dead bees build up near the reduced entrance, this can block the opening to the hive and prevent bees moving freely.

If you do use an entrance reducer be sure to place it with the hole facing upward so that dead bees don’t obstruct the passage.

Feeding Honey Bees in Winter

Many bees can be lost over winter due to starvation if food stores aren’t adequate. In the build up to winter when you inspect your hives one of your jobs is to judge whether colonies have sufficient honey stores. If for any reason the stores are low as they go into winter, you will need to feed your bees. Your objective is to keep bees from starving in case they run out of honey stores.

Keeping some honey from last seasons harvest is good practice. There is no better food for bees (however only feed them their own honey. Honey from another source can be dangerous for bees because it might contain bacteria and viruses from other colonies).

If you don’t want to feed honey, you can provide some form of supplemental feed for your bees. You normally stop liquid feeding (sugar syrup) around the middle of October. In cold conditions (below 10°C/50°F) it’s best to feed bees with fondant (also sometimes called bee candy). Unlike syrup, fondant is dry. Feeding fondant is better than sugar syrup when the temperatures drop because it reduces the risk of moisture building up inside the hive. The syrup becomes too cold to drink from the feeder, so it’s no good to your bees.

Fondant is placed above the bees, on top of the box where the bees will be wintering (usually the brood box). There are various ways to feed fondant. Some beekeepers simply place the fondant directly on top of the frames of the brood box. You can then surround the fondant with an empty super, and put the covers back on. If you’re only supplying a small amount of fondant then you can also use a feeding shim or eke to create some space around the fondant. This can end up a bit messy, with sugar sliding between the frames as warm moist air rises in the hive, disintegrating the fondant. But it also has the advantage of putting the fondant where the bees can get to it easily. This is especially good in emergency feeding situations.

Alternatively you can make or buy a candy board. A candy board sits on top of the brood box and under the inner cover. This is a box about 2 ½ inches tall with a wire mesh fixed to the bottom and a ventilation hole in the front. These provide both food and ventilation.

When you add your fondant, be sure to place it in the center where the bees can get to it.

Ventilating hives in the Winter

Bees hate moisture more than they do the cold! Bees can be pretty good at surviving cold temperatures, but if the hive is cold and damp the colony will struggle, or even die.

The problem in a nutshell is as follows… A cluster of bees generates heat and moisture. Warm moist air will rise to the top of the hive where it hits the inner cover. If this humid air can’t escape and the inner lid is cold (which is especially likely in winter) then condensation will form on the underside of the cover and drip onto the bees below. This wetness seriously affects the bees ability to maintain the correct temperature.

Ventilation seems to be a sticky question among beekeepers and individuals seem to have their own personal ways of dealing with it (or not). Exactly how much ventilation is needed, and when, seems to be a mystery. That being said, ventilation does help provide a level of humidity control.

There are various ways of ventilating hives over the winter. Some people simply prop up the cover during winter to allow better air circulation. Another method I’ve seen is to use a vented super. These can be purchased from your hive manufacturer, or you can use a shallow super with a series of holes drilled into it. Just make sure you attach a mesh screen over the inside of the holes to avoid unwanted intruders! The holes can then be plugged with stoppers (made of rubber for example) which can be left in place or removed according to the amount of ventilation judged necessary. If you pull out a stopper and there’s condensation on the inside this can be taken as a sign that more ventilation is required. Pull out another stopper!

The inner cover​

Hives have an inner and and outer cover. Inner covers are like the ceiling of a hive and the outer cover is like the roof. In wintertime it is generally recommended to place a sheet of insulation over the inner cover to prevent it from getting cold. This is to counteract the possibility of condensation forming on the inside of the inner cover. But it also helps to retain heat inside the hive (75% of a hives heat is lost through the top).

Inner covers have an oblong hole in the top which helps provide ventilation. One argument is that a hive loses heat as well as moisture through this opening (in an ideal winter setup a hive needs to retain heat but control moisture). In an attempt to neutralize this some people use a moisture board in place of the inner cover during the winter. You place the moisture board on top of the feeding shim or super, then you add a sheet of insulation before replacing the outer cover. The moisture board is designed to soak up humidity and wick it to the outside through the sides of the board.

Remove the Queen Excluder

If used, beekeepers remove the queen excluder to avoid what is known as isolation starvation. Depending on the severity of your winters, beekeepers leave one or more supers of honey stores for the bees during winter. Alternatively you might leave a vented super with fondant in it as supplemental feeding for your colony.

In either case, leaving the queen excluder in place means the bees cannot reach the food in the supers. Bees go into a winter cluster with the queen bee at the center of a huddle of worker bees. The queen cannot migrate toward the supers if the queen excluder is in place, and the bees won’t leave the queen exposed to the cold.

Not everyone uses a queen excluder, but if you do, now is the time to clean it and pack it away for the following season.

Insulating Beehives for Winter

We’ve talked about insulating the roof, which is where most of the heat is lost, but depending on your climate you may also want to insulate the outer walls of your hives. But keep in mind that only 25% of a hives heat is lost through the side walls.

A winter cluster of bees sets up a system of food sharing to help keep up their energy. If conditions are warm, the cluster can move to another part of the hive that contains honey stores. When warm, the cluster tends to be bigger and the bees have more freedom to move. But in extreme cold the cluster contracts and cannot move. If bees can’t reach nearby food stores, the colony will die of starvation. Come the spring, beekeepers can discover a dead colony just a few inches away from honey stores!

The aim of insulation is to help retain heat inside the hive to create warmer conditions which encourage movement so bees can “break cluster” to reach food throughout the winter. Studies have shown that insulated hives have more relaxed clusters and bees have more ability to move around than non-insulated colonies.

Some beekeepers also argue that insulation can sometimes have the opposite effect, and prevent the interior of hives from warming up when the outside temperature increases. But again, studies show that bees in insulated hives react to outside temperatures at pretty much the same speed as non insulated hives.

I’ll leave it to you to judge whether or not to insulated the outside walls of your beehives, but if you do, the best material to use these days is probably foam board. This kind of insulation is resistant to moisture and provides an excellent level of insulation. The insulation value does not degrade even when wet. It’s also easy to cut and shape so you get a good fit for your beehive.

Keep your Hives Dry

Even if you choose not to insulate the sides of your walls it’s highly recommended that you wrap your hives in a material that will help to keep them dry. Traditionally beekeepers use building paper for this. (Building paper is kraft paper saturated with asphalt for waterproofing. It’s also commonly known as tar paper).

Building paper has a few advantages. For a start it’s low cost. It performs the function of keeping the hive walls dry. And because of its black color, it will absorb heat from the sun on brighter winter days and help warm the hives.

It will also provide a barrier against the wind in case the hive has any unsealed openings. But this does not replace a windbreak which is important for diverting cold wind which reduces the surface temperature of the hives…

Shelter from wind

Windbreaks are just as important as the insulation of your hives. Long periods of wind can cool a hive rapidly and this puts a lot of stress on the colony. The further north you are then the more important it becomes to setup good windbreaks.

Windbreaks are something you might want to take into consideration when you first locate your beehive. Natural windbreaks such as bushes and vegetation are ideal. A small barn or outbuilding will also do fine. Anything that deflects the cold wind and prevents gusts hitting the hives.

Some beekeepers relocate their hives for the winter to take advantage of a more sheltered setting. A winter site should be at least two miles away from its original location (Moving a hive is stressful for the colony so I would only recommend doing this when really necessary). As well as being protected from prevailing winds the new site should not be prone to flooding. Ideally you should pick a spot with as much winter sun as possible. The sun will help to warm the hive and it also encourages the bees to leave the hive on warmer winter days. This is beneficial to the bees and allows them to take cleansing flights and eliminate waste from time to time.

Failing that, you can easily setup a manmade windbreak to protect your hives from prevailing winds. I’ve seen a lot of beekeepers use a few well placed bales of straw to shield their hives. Otherwise, you can build a solid fence or barrier made from whatever you can lay your hands on.

General Hive Maintenance

When you close up the hive make sure all the parts are a good fit. You want it to be as airtight as possible. If the hive is leaky, bees will use propolis(bee glue) to seal the openings. This process is a chore for bees and uses up precious energy.

Make sure the outer lid is watertight and that the beehive is generally weather proof. You might also want to clean the hive floor or replace it if necessary.

To help hold down the lid most beekeepers place a heavy weight such as a large stone or a brick to prevent the lid lifting off during windy conditions. Many people also use a hive strap which wraps around the hive to hold everything in place. This is especially useful in winter when the weather worsens.

I hope you find the above tips handy for winterizing your colonies and best of luck to you and your bees during the cold season…