Managing a dearth
Updated
What it is
Between the spring flow and the fall one, most regions have weeks where little or nothing is blooming. The colony is at peak population precisely when forage disappears, which is the worst possible combination.
Penn State's seasonal guidance covers the pattern, and the timing shifts with region. What does not shift is that it happens, and that it happens when the colony is largest.
How you know
- Weight stops climbing, or starts falling.
- Bees become defensive at the entrance and during inspections.
- Foragers investigate everything, including your extraction shed and other hives.
- Stores are consumed rather than added to.
What the colony does
It reduces brood rearing, because raising bees it cannot feed is a losing trade. It may evict drones. And it starts looking for nectar wherever it can be found, which includes weaker colonies, which is where robbing comes from.
Queen rearing also becomes much harder. A September dearth constrains how many queens can be raised sharply compared with spring, which matters if you had planned to requeen late.
What you do
Reduce entrances on weak colonies before the dearth, not during it. Feed if stores are genuinely low, and feed inside the hive rather than in the open, because open feeding in a dearth is how a robbing frenzy starts.
Work quickly and keep everything covered. This is the same instruction as harvest day, and it is the same reason: late summer is when an open frame of honey is an advertisement.
What not to do
Do not inspect for interest. Do not open feed. Do not take honey off a colony on the assumption that what you weighed in July is still there. And do not read defensive behavior as a bad queen, because a colony in a dearth is simply a colony in a dearth.