Colorful beehives under snow
(Image credit: Julie Clopper)

Bees are some of our most important pollinators and are crucial to our food sources and biodiversity. Beekeeping is a fun hobby that can help keep the insects in your garden for maximum blooms and yields. It also helps increase the general population of these threatened insects. Keeping bees over winter takes a bit of preparation, but knowing how to preserve the colony to sustains its usefulness year after year.

What Do Honey Bees Do in Winter?

Bees have a fascinating life cycle. They begin as eggs, progress to larvae, then pupa, and finally become adults. Honey bees during winter are still active and do not hibernate. Instead they stay in the hive and continuously fan their wings. This activity keeps the hive warm during winter.

When temperatures drop to 50 degrees Fahrenheit (10 C), the colony kicks out the drones or males. This is because they have no further purpose in winter and would strain the colony's resources. The queen slows and finally stops egg production. Female workers store honey to feed them over the winter. The colony's fate rests in the amount of food the workers are able to store.

When to Start Winterizing Beehives

Near the end of summer it is time to prepare the hives for winter. Bees will naturally prepare for winter, but they can use some assistance to prevent huge losses. Losses of 10 percent are common but higher numbers can threaten the health of the colony. In northern climates, begin to prepare colonies in August to September. Warmer climates can wait a month or more to begin to winterize bees.

Preparing Bees for Winter

The most common reason colonies fail in the cold season is lack of food. Varroa mites in the colony can also take a toll. These tiny pests feed and reproduce on larva and pupa, reducing populating and transmitting disease. Here are some tips to prepare for winter:

Make Sure Colonies Are Healthy

The first thing to do is check the level of Varroa mites. There should be fewer than 1 mite per 100 bees, or treatment will be necessary. Next, check to see how much honey they have stored. Lift the hive with one hand. If it is difficult to shift, there is probably enough food. There needs to be 90 pounds (41 k) of honey reserve to sustain a colony in a long northern winter.

Choose Where to Overwinter Bees

Relocating the hive is an important part of beehive winterization. Cold is only one factor that can impact their survival. Wind and dampness will also cause deaths. Moving the hive to a protected location can enhance survival rates. Avoid low areas that will hold damp, moist air, but also do not put the hive at the top of a hill, where cold, drying winds occur. If possible, site the hive under trees that will provide a natural windbreak.

Moving a hive can be difficult and dangerous, so it's easier to protect the hive where it is, covering it with tar paper, burlap, straw, or other material to buffer the wind.

Insulate the Hive for Winter

A wind buffer will provide some insulation for the hive and should be prepared in October. Older hives will have cracks and can be bent, allowing the weather in. Replace older brood boxes if necessary. Wrap the hive in an insulating layer of corrugated cardboard or roofing paper. This may be stapled to the sides of the hive with an overlap and reinforced with twine.

Cut holes at the upper and lower entrances of the hive. Turn the hive so the entrances are away from the wind. These entrances are crucial to allowing CO2 to dissipate, air to flow, and allow for removal of dead bees and other debris.

How to Care for Bees During Winter

If the beehive is too light to have enough honey, feed the bees in late summer to early fall. Use a 2:1 ratio of cane syrup and honey. Once freezing temperatures begin, remove the syrup.

Feed Your Bees

Syrups will not sustain the bees during winter. If they lack honey they will collect at the upper entrance on warmer days. This means you will have to dry feed the bees. The recipe is simple and called bee candy. Mix sugar with half as much water and boil until the temperature is 225 degrees Fahrenheit ( 107 C). Take the mixture off the heat and stir in dry pollen substitute. Add enough dry pollen to begin to tighten the mixture and then quickly pour it into cookie sheets to cool. It may be broken up and placed in the hive when outdoor temperatures are around 50 degrees Fahrenheit (10 C).

Make Sure Hives Have Good Ventilation

Overwintering bees will consume honey and exude CO2. The CO2 needs to get out of the hive or the bees will die. Leaving entrances open also allows any bees or larvae that died to be removed. Excess moisture produced by the bee’s metabolism can air dry with a little provided ventilation. Bees will also need a way to get outside during warm spells. Generally, the two entrances left exposed after wrapping the hive will be sufficient.

Plan for Next Year

Winter is a good time to reassess supplies, repair old frames and acquire any spring supplies. If you keep drone brood frames and protein supplements in the freezer, winter is a good time to clean and defrost the unit. Assemble new hives if necessary. Plan for spring emergency feeding by having corn syrup and water solution handy.

Frequently Asked Questions

How Do I Know If Bees Have Enough Honey For Winter?

It's best to leave more than the insects require to ensure they have enough. Hefting the hive will assess how much there is inside. When temperatures are warmer, check the box in February. Lift the top cover. If the bees are clustered there, they will need supplemental feeding.

Will Bees Die in Winter?

Some bee death will occur over the winter no matter how carefully the hive is protected. This is natural and the bees will clean the carcasses out. A survival rate of 90 percent is the benchmark for a reestablished spring colony.

Bonnie L. Grant

Bonnie Grant is a professional landscaper with a Certification in Urban Gardening. She has been gardening and writing for 15 years. A former professional chef, she has a passion for edible landscaping.