Getting Your Beehives Ready for Cold Weather

Autumn officially arrived on Sunday, Sept. 22, and the month of October brings with it crisp days, cool nights, and the start of the annual fall festivals — complete with hayrides, pumpkin patches and corn mazes.

The autumnal equinox is one of two moments each year when the sun is directly above the Equator, resulting in nearly equal lengths of day and night. This equinox signals the beginning of autumn and the end of summer’s warmth.

As the season unfolds, the leaves on deciduous trees begin to change, creating stunning displays of red, orange and yellow foliage.

It never fails to amaze me how much noise a one-pound gray squirrel can make running through the freshly fallen leaves.

Without a doubt, fall is my favorite season visually, and it always serves as a reminder that our beekeeping season is coming to a close.

As most crops are planted in spring and grow through the summer, autumn marks the time for harvest.

From late September to early December, it’s a busy season for both farmers and beekeepers. While farmers tend to their fields in summer, their true downtime doesn’t begin until colder weather settles in, much like us beekeepers who have worked hard throughout the warmer months.

If you have the chance, it’s always a rewarding experiment to set aside and harvest a frame of honey from different times throughout the season. This allows you to observe the seasonal differences in color and taste.

May, July and September honey can look and taste dramatically different. As fall sets in, newer beekeepers might notice an unusual smell near their hives, something akin to dirty socks.

This is likely due to your bees foraging on goldenrod. You might also see foragers returning with a white stripe between their wings, a good sign that they’ve been foraging jewelweed.

Many beekeepers spent September treating their colonies for Varroa mites, and for good reason. It’s often the first time since summer that weather conditions and hive setups allow for a wider range of treatment options.

No matter what you choose, I strongly recommend following the manufacturer’s label instructions closely when using and applying miticides.

You may not realize it, but there are big changes going on in your colonies at this time of year. The summer foragers that have been working tirelessly over the last few weeks are systematically being replaced.

As they slowly die off, winter bees are taking their place. Winter bees are workers that emerge near the end of the foraging season.

These are the bees that determine whether our colony will survive the winter. And because of that, we beekeepers need to pay more attention to colony health and nutrition at the time these bees are being reared.

This is arguably the most important generation of bees that will be raised all year. Between late August and early November almost the entire population of bees will have changed.

Winter Bees

The colonies you have now will contain a totally different workforce by the end of the year. The winter bees are the ones responsible for getting the colony from mid- to late autumn through to the following spring.

They are sometimes termed diutinus bees, Latin for long lived or long lasting. These are the bees that thermoregulate the winter cluster, protect the queen, and rear the small amounts of brood during the cold, dark winter to keep the colony ticking.

In winter, unlike other insects, honeybees don’t go dormant. Instead, they stay mildly active all winter inside the hive, clustered together in a ball, consuming honey, and flexing their flight muscles to generate heat.

In the fall, the queen slows down laying eggs and will in most instances stop altogether before the really cold weather arrives. Before she does, she lays a special caste of bees, called the winter bees.

These winter bees are physically different from their summertime sisters beyond having a longer life span.

When they are larvae, the winter bees are fed a diet that is low in protein (pollen), compared to the summertime bee larvae that receive lots of pollen.

This pollen-scarce diet causes the winter bees to develop an extra-large “fat body” — that special insect tissue that regulates their metabolism and produces vitellogenin, an amazing substance that enhances the bees’ immune system and increases its life span.

The transition from bees using resources to rear brood to storing them in their fat body begins in September.

This transition is a process whose rate depends on the hours that they have spent in cluster.

This allows the winter bees to live 6 months instead of 6 weeks and tolerate much lower ambient temperatures.

Because of this difference in their physiology, they are considered by many as a separate and unique caste of bees.

Prepping for Cold Weather

One of the most impactful things a beekeeper can do to help his or her colony prepare for the winter is to ensure they have the resources to survive the long, cold months ahead.

While it may be tempting to wait and see if the fall flow provides a natural boost, in most parts of Pennsylvania it’s wiser to start supplemental feeding in September, or very early October.

Once your honey supers are off for the last time, evaluate your colony’s stores and begin feeding if needed.

Remember, the generally accepted number is that a colony has 60 pounds of stores to make it through winter. If you wait until the fall flow is over, you may encounter issues with feeding due to cooler nighttime temperatures.

Bees are far less likely to take syrup when temperatures drop below 50 degrees, and if it gets too cold at night, the syrup may not warm up enough during the day to become attractive to them.

There are a few other things to consider. For instance, if you’re feeding after all the other forage is gone, you will ramp up the risk of robbing because your hives will be the only remaining resource for other colonies’ foragers.

It’s better to get the feeding done when bees are still actively foraging. If you find yourself behind the eight ball, feed inside the hive.

You can accomplish that by adding an empty super where the syrup is safe from would-be robbers.

It’s recommended in the early fall to feed a syrup mix of 2-to-1 (sugar to water, by weight) and 3-to-1 in the latter part of the season.

A concentrated mixture reduces the energy required by the bees to dry it down to honey-like consistency, and also reduces excess moisture in the hive, which can be a problem throughout the winter.

Be certain to use only granulated cane or beet sugar when making syrup for bees — never powdered sugar, brown sugar or organic sugars, which may contain indigestible particles.

At these concentrations, you will likely need to use some heat to get the sugar to properly dissolve in the water. Do not allow it to overheat or caramelize.

Boil the water, not the syrup, as it prevents the buildup of toxic compounds that can harm your bees. Once it’s just shy of boiling, take it off the heat and stir in the sugar.

To help prevent mold, add 1 teaspoon per gallon of apple cider vinegar. If you have them, surplus frames of capped honey are the easiest way to add stores to a hive with a shortage.

Use them to replace undrawn foundation. Conversely, empty drawn comb can be added to a colony that needs additional space to store syrup.