By Valerie Reinhardt, Horticulture Manager

The goldenrods and asters have faded (mainstays for honeybees collecting the last of the season’s nectar), the nights are longer and temperatures have dropped. What happens to the honeybees? What goes on in the hive in the winter? The European honeybee, a non-native, is the only North American bee to overwinter in the hive as a colony. Bumble bees, mason bees and other native bees all die off, except mated queens that hibernate for the winter.

In the hive, the bees get ready for winter and the drones are forced out. As the days shortened in October and November, the queen went from laying 1,500 to 2,000 eggs a day to around 25 a day. 

In the fall, beekeepers busily prepare their hives for the winter. They do last-minute checks to see that the hives have enough honey to make it through the winter; if there is not enough honey, they do a fall feeding of sugar water or high fructose corn syrup. Beekeepers gather the last of the harvestable honey, making sure to leave enough for the colony and bring the size of the hive down to just a couple of suppers. They check the health of the bees and medicate if needed. Small colonies often do not survive the winter, so the beekeepers combine them with other hives to make sure there are enough bees to warm the hive. Honey stores, health and the size of the colony all make a difference in making it through a winter. Some beekeepers wrap their hives in black tar paper or build a wind break to help keep the cold out, but the bees themselves heat the hive.

Hives with fall feed getting ready for winter

When temperatures fall below 55 degrees, bees ball up in the hive with the queen in the center. Insects are cold blooded, but bees can generate heat by flexing their flight muscles. They do this to keep the core of the hive warm. The bees rotate from the inside of the ball to the outer edges, taking turns heating the hive. The bees on the outside may become inactive due to cold but when pushed to the center, they warm up and take the place of those in the center. Doing this can keep the core of the hive a toasty 90 degrees. In our area, it’s not the cold that will kill the bees but starvation when they are unable to move to the honey stores. This can happen if the size of the cluster is too small to keep the colony warm during long periods of deep cold.

Good ventilation in a hive is important even in winter, as this allows excess moisture to leave the hive. A vent hole at the top of the hive allows warm moist air to exit the hive. Cold damp air can lead to sickness and death in the hive.

Bees need the occasional break in the weather during the winter months when temperatures are above freezing. On warm days they will exit the hive for cleansing flights (voiding feces). When unable to do these flights because of cold weather, bees can become sick which can lead to hive decline. You can sometimes see them exiting the hive even with snow on the ground if the outside temperature is warmer than 60 degrees.

Honeybees taking a mid-winter cleansing flight

When the days start to get longer in January, queens resume egg laying and steadily increase to laying 1,500 to 2,000 eggs a day by March and April. The cluster of bees will move around in the hive to access the honey stores and continue to generate heat as needed to keep the queen and brood warm and alive.

If there is a long warm spell mid-winter it can cause the bees to use up their honey stores and lead to early brood rearing. Bees will not move away from the brood chamber to feed, which can lead to starvation. This is especially hard if followed by a deep cold spell.

As the first truly warm days of spring arrive, maples and dandelions will begin to bloom. These plants are important to honeybees because they supply the first nectar and pollen of the new season. At that time, beekeepers go back into the hives and see how the colonies faired during the winter and start a spring feeding of sugar water to give the bees a jumpstart to ensure their health. When the bees are happily collecting pollen from the bright yellow dandelions and bringing it back to the hive, you know the queen is laying and the hive is ready for a new season.