Overwintering honey bees in single-deep hives

For the second year in a row, I’m overwintering my bees in single-deep hives. After years of running double deeps, and three years with triple deeps, I went to singles beginning about sixteen months ago. My decision was prompted by Thomas Seeley’s discussions of single deeps and the fact that very large colonies seem to have disproportionately high mite loads. But most persuasive were the infrared photos I had taken of my winter colonies.

Winter bee life in double deeps

My IR photos of the double deep hives showed that at the beginning of cold weather, my colonies were nearly always in the middle of the hive, straddled between the two brood boxes. As the winter progressed, the colonies would move up, and by late winter the entire colony was in the upper brood box. Spring inspections showed that honey remained untouched in the lowest box, while the upper box was empty of stores and the candy boards were licked clean.

The movement of the colony out of the lower box meant the area was largely unguarded. The bees used the small top entrance exclusively, and therefore had no reason to go down through the cold and empty lower box. Instead, non-bee things could (and did) move in. I’ve found both mice and shrews to be quite pleased with the arrangement: relatively warm and dry with lots of food.

I kept thinking that confining the bees to one box would be more efficient. So I rearranged frames and used escape boards to winnow all the doubles down to singles for the winter. The first year I overwintered 100% of my colonies and went into spring boiling with bees.

My winter setup using single deeps

From the bottom up, I used a bottom board with a reduced entrance, a slatted rack, a single deep 10-frame brood box, a queen excluder, a medium containing ten frames of honey, an Imirie shim with an upper entrance, a no-cook candy board with a central hole for upward ventilation, a moisture quilt, and a telescoping cover.

Although I often use 9 frames in 10-frame boxes when I’m running double deeps, with single deeps I reasoned that the last frame would give me 10% more brood comb. I used a queen excluder because, come spring, I wanted to keep the bees in single deeps and I didn’t want a bunch of bee brood in my medium boxes. To me, it seemed easier to keep them below.

Remember that I’m living in the Pacific Northwest coastal area on the 47th parallel. That means our winters are relatively mild, but they are wet and dark for a very long time. I live in USDA hardiness zone 7b, which means the average annual minimum winter temperature ranges from 5 to 10 degrees F (-15 to -12 degrees C). In a colder climate, it might be better to skip the queen excluder and let the cluster get closer to the food.

Some problems with singles

Overwintering in single brood boxes is not without management issues. Most surprising to me was the seemingly unrestrained growth in early spring. With little expansion space, I thought the colonies would stay a bit smaller. They did not. Instead, it seemed that workers were living in the honey supers and the candy boards because the brood box was already packed.

By spring, the colonies didn’t actually fit in the brood box any longer. When it was time to remove the empty candy board and the medium honey super, I used an escape board to coax them down into the brood box, but there was no room. I ended up leaving the medium boxes on until the nectar flow began, at which time I put comb honey shallows in place of the medium and put the bee-filled medium above them with an escape board.

That worked, and I ended up where I wanted to be: a single deep with a queen excluder and two shallow supers above it, each with its own entrance. Towards the middle of the flow, I added a third honey shallow on top of the first two.

Although my bees were building comb honey like never before, I planned to remove the honey supers early and give them mediums to fill for winter. This also worked well. Of course, this past spring was particularly late and long, so putting away stores after building comb honey seemed easy. It won’t always be that way.

Swarming from singles can be early and frequent

With jam-packed singles back in March, I knew swarming would come early. And it did. I split some colonies in time. Others threw swarms I was able to trap. But some got away. None of this was a surprise, of course, but due to other commitments, I wasn’t always able to be proactive.

In any case, if you successfully overwinter in singles, early swarming should be on your mind. By the end of swarm season, I had more colonies than equipment, so I ended up re-combining some of the smaller ones.

Smaller hives are easier to manage

All in all, it was a lot easier to manage the single deeps, simply because they’re single. You don’t have to lift one brood box off another, and the entire colony is clearly visible. Everything about it seemed quicker, easier, and lighter.

Nevertheless, I’m more nervous about overwintering this coming winter than last. The weather is the problem. Yesterday on Thanksgiving, all my colonies were out and about, flying, darting, and using up their food stores. I told them to go back home, but you know how well they listen.

A word about moisture quilts as thermal insulators

As an aside, I wanted to mention the moisture quilt as a thermal insulator. My primary reason for using a moisture quilt is, oddly enough, moisture. My lids, inner covers, and top bars used to drip water all winter long. But now everything inside the hive is bone dry, even the wood chips. Made properly, the quilts are magic. Still, I never thought of them as insulators, simply because it’s not that cold here in Olympia.

But earlier this fall, I was feeding some leftover syrup in baggy feeders, mostly to get rid of it before winter. After a month, two of my smaller colonies would not drink the syrup, and I realized it was too cold for them. I almost gave up, but I decided to place the moisture quilts above the baggy feeders and just leave them.

Three days later when I checked, the syrup was totally gone. The colony heat held in by the moisture quilt was enough to warm the syrup to a drinkable temperature. I’m sure it’s that same colony-generated heat, held in by the moisture quilt, that keeps the wood chips dry all winter long. I had always thought it was simply the ventilation ports that kept the chips dry, but now I realize it’s more complicated than that.

The future of singles in my apiary

I don’t know if I will continue with single deeps or go back to doubles. Certainly, there are issues with both methods, and if you live in an area where swarming is a problem, singles might be difficult. But overall, I find management of singles is easier and lifting is minimized. Although my honey production per hive was way up this past season, I think I have to attribute that more to the nectar flow than the hive configuration. But still, singles are my management plan for the immediate future.

Rusty
Honey Bee Suite