Entry 03 · Swarming
Swarm season: the two weeks in May I cannot look away
Most of what I know about swarming I learned in a fortnight each May, largely by being one inspection behind. The bees are not being difficult; they are doing the only thing a healthy colony has ever wanted to do.
- At the hive
- 28 April 2025
- Typed up
- 14 July 2025
- Reading
- 7 minutes
- Stand
- the Taunus foothills above Frankfurt
The signs I trust and the ones I do not
Play cups mean nothing. There are three or four in every colony I keep, empty and polished, all season long, and for one entire spring I treated each of them as an emergency. What matters is what is inside. A cup with an egg standing in it is a colony thinking about leaving; a cup with a fat larva floating in royal jelly is a colony that has decided, and the clock on that decision runs to about eight days before a queen is sealed.
The other signals are softer and I trust them less on their own. A brood nest with no room left in it, drones in numbers from the middle of April, a colony gone suddenly quiet on a flying day, bees hanging outside the entrance in the evening. Any one of those can mean very little. Together with a charged cup on the bottom edge of a middle frame, they mean I have a decision to make on this visit rather than the next one.
Nine days, and why the interval is the whole method
A queen cell is sealed on the ninth day after the egg is laid, and a colony usually swarms within a day or two of sealing. Every useful thing in swarm control follows from that one number. If I go through a colony thoroughly, destroy every charged cell, and then come back inside nine days, no colony can get from a fresh egg to a sealed cell and out of the box between my visits. Ten days is not nine, and I have proved that the hard way.
Thoroughly is the difficult word in that paragraph. A cell tucked into a fold of comb at the bottom of the third frame counts, and one missed cell makes the whole visit pointless. I check both faces of every brood frame in full sun, with my back to the hive and the frame tilted so that the bottom edge is lit, and I still miss them. Which is why the interval matters more than my eyesight: a cell missed on one visit is usually still there and unsealed on the next.
Written on the card
- Egg to sealed queen cell: nine days
- Every brood frame, both faces, in good light
- Come back inside nine days or the interval is worthless
- One missed cell makes the entire visit decorative
The morning a cast left over the hedge
On a Saturday in the middle of May last year I was in hive two, working through a colony whose cups I did not like, when the noise behind me changed. Hive four, which I had checked six days earlier and written down as quiet, was emptying into the air. I stood in the middle of it, entirely useless, and watched the swarm drift over the hedge, settle in a plum tree on the far side, hang there for twenty minutes and then go somewhere I could not follow.
The mistake had been in my notebook the whole time. My note on hive four read cups empty, no eggs, check next week, and next week had quietly become nine days because of a wet Wednesday and a late train. The colony had not done anything unusual at all. It had been given ten days instead of nine and it used them. I keep that entry exactly as it was written, with the date circled, because a tidied record would have let me call it bad luck.
Splitting on purpose instead of chasing
I stopped trying to prevent swarming and started doing it myself, which is less elegant and far more restful. If a colony in early May is strong, full and showing charged cells, I take the queen and a frame of brood and stores into a second box a few metres away, and leave the flying bees and the cells with the old hive. The colony gets roughly what it wanted, I keep the bees, and nobody has to stand in an orchard looking upwards.
The cost is honest enough: two smaller colonies instead of one large one, and less honey off that stand in that year. I have decided I do not mind. A split made on purpose in the second week of May usually gives me a laying queen by the middle of June, and if the new queen fails I still have the old one two metres away. Left to itself, a colony that swarms takes half my bees over the hedge and leaves the rest a queen I never saw mated.