Rethinking the triple-deep hive
In spite of the HopGuard fiasco of this past winter, some of my hives pulled through. With one exception, the colonies that survived were either in triple-deep Langstroths or a top-bar hive.
I get a lot of questions about the wisdom of using triples and my usual answer is that the size of the hive should be commensurate with the size of the colony. It seems logical that a colony should not be crowded into a small hive lest food shortages occur, nor should the colony be overwhelmed by a large hive that cannot be patrolled and kept warm.
One of the interesting things about losses is that you get to see what works and what doesn’t under adverse conditions. All my hives were treated the same way last fall, but it is obvious now that the large-volume hives did better. I don’t know the exact volume of the top-bar hive, but my rough calculations show it to be larger than a double-deep Langstroth, but smaller than a triple-deep.
So what is the difference? Of the hives that died, each had ample supplies of pollen and honey, and no obvious signs of disease other than deformed wing virus (which is transmitted by mites). But since all the hives were treated at the same time with the same (inadequate) regimen for mites, why did the larger-volume hives survive? The truth is, I don’t know.
I don’t think that the number of bees was much different in the doubles and the triples in the fall, but the bees were more spread out. The triple-deep nests were more-or-less in a column rather than a sphere. Hive inspections showed the brood nests spanning all three boxes in the very center.
Here are some theories:
- A larger brood nest encourages the queen to raise more brood. Even though more brood yields more mites, the vast number of clustering bees is able to overwhelm the phoretic mites.
- Triple deeps allow the bees more room to move straight up, rather than move laterally, for food. This idea, though, does not account for the top-bar bees which have to move laterally in any case.
- A fall nectar flow, especially one occurring after the honey supers have been removed, encourages bees to backfill the brood nest with honey. Sugar syrup fed in the fall does the same thing. As a result, the queen has little room to lay, so she slows egg production earlier than she should. The lack of brood forces the colony into winter with an older population of bees that are not robust enough to raise spring brood. By using three deeps, you give the bees more room for storage while allowing the queen more space to lay eggs in the fall.
- A larger brood nest yields more bees to help keep the colony warm and hygienic. Even though a large colony uses more food, it is available in the three boxes.
- Triple deeps have better ventilation because a taller hive increases the “chimney effect.” Damp air and mold spores go out the top; fresh air comes in the bottom.
Whatever the reasons, advocates of triple-deep hives report fewer winter losses, less need for spring feeding, earlier build-up of spring populations, and fewer swarms. I was never a believer. But based on my own experience this year, I think I will plan for triples in the coming season.