Combine weak colonies in fall to build viable clusters

Assess colony populations in September and merge any colony covering fewer than 6-8 frames of bees into a stronger unit using the newspaper method. A viable winter cluster requires roughly 20,000-30,000 bees -- two weak colonies left separate almost always both die, while combined they often survive.

Why It Works

The winter cluster generates heat through coordinated muscle micro-contractions. A larger cluster has a lower surface-area-to-volume ratio, meaning less heat loss per bee and lower honey consumption per individual. Colonies below approximately 10,000 bees cannot sustain the 34-35°C core temperature through prolonged cold snaps and collapse. Combining doubles the population and the honey stores available to the merged unit.

Steps

1. Assess each colony on a mild day in early-mid September by counting frames covered with bees
2. Select the stronger queen and remove the weaker queen 24 hours before combining
3. Place a sheet of newspaper with a few small slits between the two hive bodies -- bees chew through over 1-2 days, allowing gradual scent merging
4. Remove the empty equipment once the colonies have fully integrated (3-5 days later)

Tips

• Treat both colonies for varroa before combining to avoid transferring high mite loads into the merged unit
• Ensure the combined colony has adequate stores -- at least 60-80 lbs of honey (roughly a full deep super) for northern climates
• If neither colony has a strong queen, consider requeening with a mated queen from a reputable supplier before combining