Preparing Your Colonies for Winter: The Autumn Checklist

Winter losses are decided in autumn. The choices you make between September and November—feeding, treating, consolidating—determine whether your colonies emerge strong in spring or become empty boxes. This is the most consequential management period of the beekeeping year.

The Autumn Timeline

Step 1: Varroa Treatment (September)

This is the single most important autumn task. Colonies that enter winter with high mite loads produce weakened "winter bees" that die before spring—dooming the colony even if it has plenty of food.

Why Timing Matters

Winter bees are physiologically different from summer bees. They develop larger fat bodies and can live 4–6 months instead of 6 weeks. But they're produced in September and October—if mites are feeding on these developing bees, they emerge weakened and short-lived.

Treat immediately after the honey harvest. Every day of delay means more mites reproducing on the winter bee generation.

Treatment Verification

After treatment, do a follow-up mite wash 2 weeks later. If counts are still above 1%, consider a second treatment with a different mode of action.

Step 2: Assess Colony Strength

Not every colony deserves individual winter preparation. Weak colonies—those covering fewer than 5 frames of bees in September—are unlikely to survive winter regardless of feeding. They're also a varroa sink that threatens your stronger colonies.

The Hard Decision

Combining weak colonies with strong ones using the newspaper method is straightforward and gives both populations a better chance.

Step 3: Feed for Winter

After removing the honey harvest, most colonies need supplemental feeding to reach their target winter weight.

How Much to Feed

The target weight depends on your climate. Weigh the complete hive (bees, boxes, frames, stores) and calculate the deficit:

• Target total weight: Equipment weight + 18–30 kg of stores (depending on climate)
• Feed conversion: 1 liter of 2:1 syrup is approximately 0.7 kg of stored honey equivalent

Feeding Tips

• Use 2:1 sugar syrup (2 kg sugar to 1 liter water) for autumn feeding—the low water content means less evaporation work for the bees
• Feed in large volumes to encourage rapid storage rather than consumption
• Stop feeding when nighttime temperatures consistently drop below 10 degrees C—bees can't process cold syrup
• Place feeders directly above the cluster for easiest access

Step 4: Requeen If Needed

Autumn is your last chance to assess queen quality before winter. A colony with a failing queen in September will not survive to spring.

Signs of a failing queen: - Spotty brood pattern with many empty cells - Drone brood mixed into worker comb - Colony size declining despite adequate forage - Excessive supersedure cells

If requeening this late, use a mated queen from a reputable breeder. There isn't time for the colony to raise their own.

Step 5: Physical Winterization

Mouse Guards

Install mouse guards or reduce entrances to less than 8 mm height by early October. Mice seek warm shelter as temperatures drop, and a beehive is irresistible. A single mouse can destroy comb, disturb the cluster, and cause colony death.

Ventilation

Moisture kills more colonies than cold. Ensure adequate ventilation:

• Leave the screened bottom board open (or use a solid board with a rear ventilation gap)
• Ensure the inner cover allows some air exchange
• Consider a moisture quilt—a box filled with wood shavings above the inner cover that absorbs rising moisture

Wind Protection

Provide windbreaks if your apiary is exposed. Straw bales, temporary fencing, or wrapping hives with roofing felt (tar paper) all help. The goal isn't insulation—it's reducing wind chill on the cluster.

Step 6: Record and Plan

Before stepping away for winter, record the status of each colony:

• Mite count (post-treatment)
• Estimated stores (weight or frame count)
• Queen age and quality
• Colony strength (frames of bees)
• Any concerns or spring priorities

This data feeds directly into your spring planning. You'll know which colonies to check first, which might need early feeding, and which queens should be replaced.

The Winter Mindset

Once winterization is complete, the hardest part for beekeepers begins: leaving the bees alone. Resist the urge to open hives on warm winter days. Every inspection breaks the propolis seal, releases heat, and costs the colony energy it can't afford to spare.

Instead, observe from outside. Listen for a gentle hum when you place your ear against the hive. Watch for cleansing flights on mild days. Heft the hive occasionally to monitor stores. And plan for spring—because it will arrive faster than you expect.