How to overwinter your Flow Hive in extremely cold climates

There are a number of factors to consider when overwintering a beehive in extremely cold climates, which may require some specific fine-tuning.

This blog is created as guide, however, it’s extremely important to consult with local beekeepers as to common practice for overwintering bees in your local area.

Helping your bees to survive the winter (and hopefully come into spring thriving), can be a challenge as bee colony losses can be quite high in very cold climates. This is why it’s so important to ensure you undertake the right preparations or precautions, both before the temperature begins to drop, as well as during the depths of winter.

Pictured: Steven's over-wintering setup. Utah, USA.

The first step required will be to pack-down your hive for overwintering. This generally means reducing the hive down to only its brood box(es).

To remove the Flow Super:

  1. Harvest all remaining honey.
  2. Depending on what local beekeepers recommend, you may want to consider feeding this last harvest (especially if the honey was largely uncapped) back to your bees during the depths of winter.
  3. Let the bees uncap and clean up any remaining honey. Depending on how urgently the bees need to use the frame will dictate how long this will take. Sometimes it can be hours, and other times it can take days.
  4. Remove the whole Flow Super.
  5. If the Flow Frames are still a little sticky, you may want to consider cleaning them before storing them in a dark, sealed space over winter. Read more on how to clean Flow Frames on our FAQ here.

Once your hive is down to just it’s brood box(es), you may then want to consider undertaking the following factors to improve chances of a successful overwintering for your colony. These include, but are not limited to;

Entrance reduction and placement

Reducing the entrance is important too, for both ventilation reasons, and also for protecting the hive.

Most beekeepers will reduce the entrance when they begin feeding their hive with supplementary food, however you may need to do this before.
As colony numbers start to decrease, the hive can become more susceptible to robbing by other bees. You may want to consider decreasing the entrance of your hive – this can assist the guard bees in protecting the hive from robbing. You can buy special entrance reducers from a beekeeping supply store, or just use pieces of wood, some straw or any other suitable material.

Here is one example of how to create your own entrance reducer:

Some beekeepers strongly recommend creating a top-entrance for ventilation, or if you are prone to deep snow which may block the entrance during winter.

You may like to search on our Community Forum for more suggestions for both entrance reduction and creating a top-entrance – there has been a lot of discussion about both these topics.


Some beekeepers choose to move their bees to a styrofoam hive (or a hive made from insulating materials), while others wrap solar blankets (which passively warm the hive from the heat of the sun) or insulating material around the outside of the hive.

Pictured: Victor's insulated Flow Hives in Michigan, USA.

In addition to insulating the body of the hive, it can be important to insulate the roof cavity of a hive, as heat can be lost from the top.

Some ideas for insulating a Flow Hive peaked roof are;

  • Stuffing the cavity with an insulating material, such as straw, or an old woollen blanket, or thick sawdust/wood chips, or dry leaves/other organic material, and making sure to seal this area with some plywood so no pests or diseases can make this their home.
  • Creating a solar blanket on top of the roof.

Find out more information about insulating on our Community Forum.


Often beekeepers say that it is not the cold that kills the bees, but condensation.

Condensation is a big issue in overwintering a hive – if not the biggest. It is also the most likely factor in the death of bee colonies over winter.

When the internal temperature of the hive differs significantly to the outside temperature, moisture build-up can occur. This can lead to icy, frozen bees.

The best way to avoid condensation is to make sure there is adequate ventilation.
Some beekeepers believe that creating a top-entrance will allow for better ventilation. You can look for more beekeeper opinions regarding top-entrances on our Community Forum.

You may also want to consider creating a moisture quilt at the top of the hive, to make sure any moisture build-up does not drip back onto the bees. These can easily be made from a tray of sawdust or wood-shavings. Check out our Community Forum for more suggestions.

Ideal/critical mass of bees

The colony will naturally decrease the number of worker bees—and expel all drone bees—leading up to winter, as the queen bee will decrease the number of eggs she lays. This is triggered by dwindling nectar and pollen sources, as well as a reduction in daylight hours.

If your season wasn’t particularly successful, and your colony numbers aren’t strong, your bees may get too cold and may not survive the winter.

However, it’s important to note that if you feed your bees too early in late-autumn or winter, it can lead to the brood nest not decreasing in size. If you have too many bees, they may starve over winter. Too many bees can also lead to the bees not being able to evaporate moisture as easily, which also means potential bee deaths – it’s a fine balance that needs consideration.

Another important consideration is that bees which are adapted to your local area (i.e. sourced locally and not from a breeder who lives a long distance away) may also impact the colony’s ability to overwinter successfully.


Many beekeepers note that bees do not freeze in winter – they starve.

What you feed your bees overwinter is a decision that ultimately only you can make – different beekeepers will recommend different feeds. We suggest doing your own research, and consulting with local experienced beekeepers as to what food will be best for your colony.

  • Honey

Some beekeepers prefer to feed their bees with honey. They say this contains much more complex sugars, with trace minerals that the bees need.

If feeding your bees with honey, it is always recommended to feed them with their own honey stores, and often light-summer is suggested.

  • Sugar-water solution

Ragna from ByBi City Bees in Norway says that many beekeepers choose to feed their bees with sugar (specifically, sucrose)-water solution (diluted 60/40).

This can be bought ready-made, or you can mix this up yourself.

  • Fondant

Some beekeepers prefer to feed their bees fondant (which has less water-content) over sugar-water solution.

Aside from personal preference, what you feed your bees is also dependent on where you are and what your bees have access to (if feeding their own honey stores) – we recommend checking in with local beekeepers what their recommendations are.

It is also important that the bees go into winter with a few frames of pollen. If you are running a single brood box, then 1-2 frames of pollens should suffice. If you are running a double brood box, then 3-6 frames of pollen stores is considered a good supply.
Feed your bees with supplementary pollen coming into spring if they do not have pollen stores.

How much

The amount of supplementary feeding required will vary depending on local conditions and colony size or strength. Ragna from ByBi City Bees in Norway, says that they feed their bees with 16kg – a hive of average-strength (about 1 deep-brood box sized colony) will eat this amount through winter.

Kathie from Powassan Library Bee Night in Canada says about 36-40 kg of food is needed to overwinter a double-deep brood box.

When to feed

This is a region-specific question – we recommend speaking to local experienced beekeepers as to when they recommend you start, and stop, feeding.

You will find that many of the above factors are strongly intertwined, however, it is also important to note that there can be other factors which impact the success of a colony’s ability to overwinter. For example, it is said that wintering success has as much to do with the colony’s ability to communicate, share, and manage populations and brood development—even in two hives which are side-by-side, almost exactly the same in size, with the same treatments applied, there may be one that will survive while the other does not.

With temperatures fluctuating year to year, and multiple factors affecting the success of overwintering a bee colony, ultimately all you can do is your best, in consultation with other local experienced beekeepers.

Like everything in beekeeping, there are many differing opinions, and not all beekeeping advice/suggestions will necessarily work for you and your hive.

Read more about overwintering a Flow Hive on our FAQ here.

You may like to search on our Community Forum for more suggestions on overwintering in extremely cold climates, as well as anything discussed within this blog.