Practical Guide: 4.7.1 Combining colonies

The merging of bee colonies is a method used to strengthen weak colonies or compensate for losses. It must be carried out in a manner appropriate to the bees, taking into account the strength of the colonies, the season, and weather conditions. The summary below is based exclusively on the official checklist 4.7.1 of the Swiss Beekeeping Service (BGD/SSA).

Official practical guide (BGD / SSA) – Summary

Practical Guide: 4.7.1 Combining colonies

• Objective: Strengthen weak colonies or compensate for losses by combining them with other colonies to form a stronger unit.
• Principle: Combining consists of bringing together two or more colonies or groups of bees so that they become a single colony, more vigorous and capable of thriving.
• Appropriate timing: Especially when food reserves are sufficient and weather conditions are favorable; not recommended in mid-winter or under extreme conditions.
• Methods of combining:
  • Separation by grid: Place the colonies side by side with a mesh or partition until they mutually accept each other through their scent.
  • Direct combining: When colonies are calm and compatible, they may be combined directly without separation.
  • Smoke and feeding: Light smoke may facilitate acceptance, and supplementary feeding can stabilize the colony after combining.
• Key steps:
  • Identify the existing queens and decide which one will remain after combining.
  • Calm the colonies before combining (light smoke, gentle movements).
  • Place or combine the colonies according to the chosen method.
  • After combining, monitor flight behavior, reserves, and colony dynamics, supplementing with feed if necessary.
• Practical advice:
  • Observe aggressive behavior before combining; if in doubt, prefer separation by grid.
  • Avoid combining in unfavorable weather or in case of food shortage.
  • Regularly monitor development after combining (reserves, brood, behavior).

► PDF of the official aide-mémoire (FR)

► To the official aide-mémoire page (abeilles.ch)
Note: section Colony health & management → 4.7.1 “Combining colonies”.

Summary based on aide-mémoire 4.7.1. Last verification: 01/2026.

See also:

• Combining honey bee colonies
• Aide-mémoire: 4.5.2 Introducing the queen
• Aide-mémoire: 4.7.4 Management of queenless colonies
• Aide-mémoire: 4.2 Feeding