How to Combine Colonies for Better Winter Survival

Combining hives is a strategic method for improving the chances of survival for weaker colonies during winter. The process is relatively simple and involves merging a weak hive with a stronger one or combining two weak hives to form a single, stronger hive. This is typically done in late fall or a few weeks before daytime temperatures consistently drop to the 50s. Here’s a step-by-step guide on how to effectively combine hives and prepare them for the cold months ahead.

Assess Hive Conditions

Before combining, evaluate the health and strength of the hives involved.

• Check for Varroa infestation: Ensure that neither hive has a severe Varroa mite problem (more than 3 mites per 100 bees). Refer to "When and How to Test for Varroa Mites" to confirm mite levels.

• Inspect for brood diseases: Verify that the hives are free from brood diseases such as European foulbrood, American foulbrood, and chalkbrood. A hive weakened by a past high Varroa infestation might still carry harmful viruses, so avoid combining it with a healthy hive.
• Evaluate hive strength: Determine whether the hive has a sufficient bee population. A hive with three to six frames of bees is generally a good candidate for combining. Hives with two or fewer frames of bees may not be worth saving and should be shaken out and stored for future use. See “When It’s Time to Give Up on a Hive.”

Prepare for Combining

If you decide to combine the hives, follow these steps to ensure a smooth process with a better chance of success:

Step 1: Remove the Queen

• Find the queen in the weaker hive and eliminate her. If you cannot locate her, it’s acceptable to combine the hives and let the queens fight it out, though this can be risky.

Step 2: Consolidate Hive Contents

• Gather all bees, brood, and honey from the weak hive into a single box, placing them in the appropriate order—brood in the center and honey on the outside. Allow the hive to settle for about an hour after consolidating.

Step 3: Combine Hive Boxes

• Stack the stronger hive on top of the weaker hive’s consolidated box. If necessary, you can use three boxes initially. Example: Combine a double deep box with a single. You can usually remove the third box after a month or two once they consolidate and it is empty.

Step 4: Close and Finalize

• Close up the hive. While some beekeepers recommend placing a sheet of newspaper between the two hive boxes to help the bees adjust to one another’s pheromones, this is not always necessary. In practice, simply joining the hives often results in minimal fighting with only a few bees lost, but if you want, the newspaper method works well too. See “Things to Consider for September.”
• Optional: You can lightly spray the bees with a sugar syrup mixed with vanilla to help them acclimate and reduce fighting.

Monitor and Maintain

Once the hives are combined, monitor the colony’s progress:

• Survival odds: Combining two weak hives gives them about a 50-50 chance of surviving the winter, which is generally better than if they had remained separate.
• Periodic checks: Check the hive periodically to ensure food stores are staying consistent as well as to watch for a drop in population that would require you to reduce the number of boxes.