What you do about winterizing your beehives depends on your local climate. Generally, make sure that your hives are:
- in good repair
- adequately protected from icy weather
- reduced to the best size for the cluster
- properly vented for moisture control
- sealed against rodent intrusion
- contain adequate honey stores for the winter
- have been checked and treated for varroa mites (and other problems).
We’ll discuss the details of winterizing. Keep in mind that the extent to which this applies to you will be driven by your local climate.
Bees In Winter
Bee activity is significantly impacted by weather conditions, particularly temperature.
As temperatures drop below 70° F (21.1° C) bee activity begins to curtail. The queen and drones stop flying first.
With temps in the mid-to-low 50s F (10° – 12.9° C), bees will begin to cluster to stay warm, workers will stop flying, and brood rearing ends.
With brood rearing ending, drones (male bees) whose sole purpose is mating, are evicted from the colony since they put additional demands on food resources.
Drones are discussed in Honey Bee Life Cycle (Why You Need To Know It)
Here’s a video of drones being evicted from one of our hives in fall:
Bees do not hibernate although the lack of activity you see makes it look that way. Even though they are not flying, you might still hear them in the hive as they work to stay warm.
Bees form a cluster, or a ball, near the center of the box. They generate heat to stay warm by shivering. Staying warm requires a lot of energy, so the bees need plenty of honey.
If it gets too cold in the hive, the bees are unable to move the cluster. Even with plenty of honey in the colony, they won’t survive if that happens.
By generating heat, the bees release water vapor causing condensation in the hive. Being wet is just as likely to kill your bees in winter as freezing.
Some winter preparation is done all summer long (fixing hive components, checking colony strength). But fall is when you really step things up.
Pay attention to the weather. Here in New York’s Hudson Valley, temperatures often permit us to complete winterizing as late as mid-November. A few years back, before we had bees, winter arrived early with a Halloween blizzard.
We start winterizing efforts by late September so that we can finish up quickly if the weather hands us a surprise. It’s a good idea to ask experienced local beekeepers about when they start winter preparations.
Check Hive Components
Weather, time and use take a toll on the hive components. Fix or replace any damaged equipment to reduce drafts. You don’t have to wait for fall to do this.
Beginners with new equipment shouldn’t have any issues.
Monitor Colony Strength
Weak hives will have trouble getting through a cold winter. No matter what you do, a lot of bees will not make it through the harsh weather. A starting population that’s too small won’t have enough bees to stay warm all winter.
If your hive is weak going into fall, your best bet may be to combine it with a stronger colony or even another weak one. (This is one reason we suggest that newbies start out with two colonies.)
Combining colonies should be done before the temperature drops significantly.
Decide which of your colonies is the strongest (“Team Strong”). You’ll need to dispatch the weaker queen (kill her). If you don’t, the queens will fight in the combined hive, and you could end up with none.
Try to get all the bees in Team Strong into their lower brood boxes. Use a bee escape board if need be. Alternatively, add a box on top for the weaker colony (“Team Weak”).
Cover the top of Team Strong’s upper box with a sheet of newspaper.
Assemble Team Weak so that the best frames of brood, honey, and nectar are in one box (or 2 boxes if you’re using all mediums).
Place Weak on top of newspaper-covered Strong. Give Weak a top feeder with sugar syrup. Add an outer cover. Don’t use an inner cover; you want the Weak bees confined to the upper box for a few days.
Bees will chew through the newspaper. Gradually, the queen’s pheromones will permeate the entire hive. By the time the newspaper is no longer a barrier, Weak and Strong will have accepted that they are now One and fighting, if any, will be minimal.
Help the bees store up food by feeding in the fall. Remember to watch for robbing. If robbing becomes an issue, reduce the entrance size or add a robbing screen.
Use a 2:1 sugar syrup. Bees need to evaporate water to store the sugar. Thicker syrup means less water means less expended energy.
See our related article What, When & How To Feed Honey Bees for sugar syrup recipes.
When bees cluster for warmth, their movement within the hive is restricted so it’s important to feed before it gets cold. We err on the side of caution and start feeding in September.
Reduce Hive Size
Get your hive down to the minimum number of boxes to house the bees and winter honey (probably 2 deeps or a deep and 2 mediums). A smaller house means a lower heating bill, I mean, less expended bee energy.
Get your brood into the center of the lowest box. Honey frames go to the sides.
Remove any queen excluders and bee escapes. Bees need the freedom to move and access food anywhere in the hive.
Keep an eye on your colony for any type of pest or pathogen. But Varroa mites are likely to be your number one problem.
See our article Varroa Mites: A Complete Treatment Guide for more details
Some beekeepers don’t like to treat for Varroa. We’d rather treat for varroa than face the devastating losses they can cause.
Varroa eggs are laid in brood cells and the mites attach themselves to the pupa. Since drones take a bit longer to develop than workers, they are more prone to varroa mites. Fall, after drones are evicted from the hive and there is little to no brood, is a good time to treat for varroa.
Without brood, oxalic acid vapor is an excellent treatment option. It requires some special equipment and careful handling. But it’s relatively quick and extremely effective.
Killing off mites before winter is a big boost for the colony.
Check Honey Stores
How much honey is enough?
The answer to this question will depend a lot on your location, actual weather results, how insulated the hive is, size of the winter cluster…..you get the idea. There is no set answer, just guidelines.
Some beekeepers go by the weight of the entire hive. An easier method is to judge by the number of full frames of honey. You can calculate the estimated weight of honey. Full frames of honey weigh:
- ~8 lbs (3.6 kg) for a deep
- ~6 lbs (2.7 kg) for a medium
- ~4 lb (1.8 kg) for a shallow
Use the following guidelines by general climate areas:
- Cold, northern climates: about 75 – 85 lbs (34.0 – 38.6 kg) or 10 deep frames
- Moderate climates: about 55 – 65 lbs (24.9 – 29.5 kg) or 6 deep frames
- Warmer, southern climates: about 35 – 45 lbs (15.9 – 20.4 kg) or 4 deep frames
This is another area where local, experienced beekeepers can help guide a beginner. Just realized, you may get 4 opinions for every 3 people you ask.
No matter how much honey our bees have going into winter, we supplement with sugar. Unable to predict how severe winter may be, we err on the side of caution. Too much food is better than too little.
We place a candy board on top full of sugar bricks. On warmer days, the bees can break cluster and access the sugar for additional food.
You can also use plain sugar (easier than bricks) or fondant (more work than bricks). These are described in our bee feeding article.
Close Up The Hive
Help the bees maintain proper temperature by closing up the hive to reduce drafts.
- If you have a screened bottom board, consider replacing it with a solid one. At a minimum, slide the drawer in to reduce air flow.
- Put on the entrance reducer with the opening on top. Dead bees will accumulate on the bottom board when it’s too cold for workers to remove them. If the opening is on the bottom, it may be blocked and inaccessible.
- Use a mouse guard. Small rodents will seek warmth in the hive and can be very destructive.
Bees warming the hive release water vapor that condense on the top of the hive. You don’t want it dripping down and wetting the bees.
- Give the hive a slight tilt forward so condensation can run off instead of dripping.
- If you place a candy board on top, leave an opening for moist hot air to vent through.
- Provide an upper entrance. This gives bees an alternative that may be closer to them and can be used if the lower opening is blocked (by snow maybe). It also helps vent out moist air.
- Consider adding a box (between the inner and outer covers) with an insulating material like burlap or wood shavings. It not only helps retain heat but can absorb moisture. Moisture control boards are also available.
Wrapping The Hive
What you wrap with, if anything, is again determined by your climate.
Don’t wrap up the hive tightly with plastic sealing. You want to reduce drafts, not keep it from breathing.
Some beekeepers wrap with simple tar paper. It’s inexpensive and relatively easy to attach. While it provides virtually no insulating value, it will reduce cold drafts. Dark colors help absorb heat from the sun.
Other similar options are available like corrugated plastic wraps that fit over the boxes.
You can provide more insulation using foam boards from your local home improvement store.
There are wraps that are basically waterproof, insulating blankets. We’ve used one called the Bee Cozy. You can see them wrapping our hives in the picture atop this article.
There’s always a danger of the hive getting too hot or the bees misreading weather signals. We think it’s worth that risk giving the bees an edge on borderline days. It might provide them with enough heat to break the cluster and access food. Without that break, they could die of starvation right next to a frame full of honey.
Vino Farm’s YouTube channel shows an innovative insulation cover he created. Check it out.
If you can, set up a permanent windbreak to protect the apiary from prevailing winds in winter. Fencing or evergreens are a good choice.
When permanent windbreaks aren’t an option, you can set up something temporary for winter.
We considered stacking hay bales but decided they would attract too many mice. Some fencing material can serve the purpose and be removed come spring.
Windbreaks should be a bit taller than the hives, directing strong winds up and over. They shouldn’t be too close to the colonies as you don’t want to inhibit air flow completely. About 5 feet is a reasonable distance.
Secure The Hive
Strong winter winds can rip the covers off your hives. If it happens and goes uncorrected, it is disastrous.
Don’t risk it. Place something heavy on top of the hive: bricks, stones, a cinder block.
We have bricks on top all year long. We don’t want the covers blown off in a summer rainstorm either.
Use ratchet straps to tie down the covers tightly.
Since you’re not going in and out of the hive, the weight and straps won’t be in your way.
Very Limited Hive Inspections
We generally stay out of the hives during winter, but it’s not an absolute rule.
If the weather has been particularly harsh, I’ll take advantage of even a moderate day to take a peek inside. I’ll check to see if there’s activity and if they need any more sugar.
In past year’s we’ve provided so much winter sugar the bees didn’t come close to making a dent in it. This past year we cut back a little. I poked my nose in one day and saw the bees taking advantage of the sugar, so I added some.
The more extreme your winter climate, the more stress is placed on your colonies. The more you can reduce that stress, the healthier your bees will be in spring.
Particularly in harsher, northern winters, you will lose colonies in winter. Losing a colony is always disheartening, but particularly for new beekeepers with only one or two hives, it is also an expensive loss. Do what you can to avoid it.
Hopefully, you took our advice and left all the honey for the bees in their first year. With a healthy, overwintered colony in your second year, you should get to enjoy the fruits of your labor soon.
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From Cornell: Winterizing Bees In Cold Climates