A split divides one colony into two. It is the commonest way for a beekeeper to increase colony numbers, and at the same time a means of preventing swarming and opening a window for Varroa treatment.

Why split

• To increase colony numbers
• To prevent swarming: Meeting the urge to divide under the beekeeper's control
• To create a broodless period: A favourable window for treatment
• To requeen: Trying a new queen in the split
• To replace losses

When to split

The colony must be strong enough: at least five or six full frames of brood and plenty of bees. Splitting a weak colony produces two weak colonies.

Late spring and early summer are suitable. The new colony must have time for the queen to mate and for the colony to prepare for winter.

Do not split when no drones are present; the queen cannot mate.

The basic method

• Frames of sealed and open brood are moved to a new hive
• Frames of honey and pollen are placed beside them
• They are moved with the young bees on them; foragers return to the old site, so extra bees must be shaken in
• One side has the queen, the other a queen cell or a new queen
• The entrance is reduced and the colony fed if necessary

Queen options

• Giving a mated queen: The fastest route; the colony gains about three weeks
• Giving a queen cell: Cheaper; delayed by the mating period
• Letting the colony raise its own: The slowest and least certain; queen quality may vary

Common mistakes

• Splitting too small. A colony formed with too few bees cannot keep warm or defend itself
• Leaving too little food. The new colony has few foragers; stores are essential
• Not adding bees when leaving it in the same apiary. Foragers return to the old hive
• Splitting too late. The colony cannot prepare for winter
• Ignoring the mite load. A split divides the mites too

After the split

• Do not open the hive unnecessarily until the queen has mated
• Eggs indicate successful mating
• Treat for Varroa during the broodless period — this window is valuable
• Add sealed brood if the colony stays weak
• Unite it if it clearly will not be ready for winter

Summary

The split is the most versatile tool a beekeeper has: it increases colonies, prevents swarming and opens the door to Varroa treatment. Its success depends on timing and on leaving enough bees and food in the new colony.