Checkerboarding Works

American Bee Journal- July, 1996

Elkton, Tennessee

I am going to go out on a limb and positively state: THE triggering mechanism for build-up swarms is nectar encroachment on the brood nest volume.

My two-part article in the Mar/Apr 96 ABJ was in the nature of a test plan. I provided some background data and a technique for reducing the inclination of the hive to swarm during the build-up. The thrust of the test plan was to provide nectar storage space continuously in the overhead honey that is consumed during the build-up, and supering in time to provide space for the new bees overhead.

In rereading what I wrote, I find a glaring omission. The chart I included had two purposes: To show the timing coincidence of swarm commit with redbud nectar availability and to present the large increase in bee population with the emergence of the third brood cycle that occurred at the same time. I failed to fully treat the population explosion in the text because it was not specifically related to the checkerboarding concept. I did mention the timing of supering, but did not tie it to the third brood cycle.

The title of this article says that checkerboarding works, I expected it to help, but I was not prepared for total success. When other hives in the area were preparing to swarm, my strongest were superseding.

We had the opportunity to compare our Yugo mid-summer starters (full hive body nucs) with a neighboring beekeeper’s established Carniolans. Both were wintered in a story and a half of honey; his in two 3/4 boxes or a hive body and a shallow, ours in a hive body and two shallows of alternated honey/empty comb. The comparison was mind boggling. His were preparing to swarm (one had already) with less than at hive body of brood and plenty of capped honey overhead. Swarm cells were everywhere.

Our mid-summer starters had pretty well filled their hive body on the fall flow, but that was all the space with which they had to work. They were generated for combining with other colonies that needed assistance in the fall. Ten were not used for that purpose. Deciding to overwinter them, we gave them two supers of 50% checkerboarded honey in the early winter. With unrestricted brood nest expansion, they had consumed most of their honey by mid build-up and were fed a gallon of sugar syrup about the first week of April. Sugar syrup, like nectar, remains uncapped and does not impede brood nest expansion. At the time the neighbor’s hives had rampant swarming preparations, my starters had their winter quarters (equivalent to two hive bodies) full of brood, and some were putting nectar in the bottom super. After seeing the neighbor’s bees, we went back to check our starters for swarm cells. The most cells we could see from the outside of a tilted up super was five and no evidence of any active work on enlargement of the cups.

This comparison appears first because we wanted to treat the down side first and the good news later. The two disadvantages to checkerboarding are the additional woodenware and comb required and the extra honey needed for build-up.

The additional woodenware required for maintaining checkerboarded overhead honey has its advantages. Space for the build-up population explosion is inherent in this configuration, permitting a longer period for mite treatment prior to supering. The cells of this additional brood space will be cycled through nectar (some more than once), brood, and nectar again during the season. This cell cycling should remove any residual chemical contamination and yield usable honey after the brood nest recedes to a lower level on the trailing edge of the flow. This purging of contaminants would need to be demonstrated by a valid test effort.

The extra honey required for unrestricted brood nest expansion is not as much as you might think. Contrary to the literature on young bee progression through different duties, during the build-up, most of the young bees graduate directly from brood tending to foraging. They wait patiently for a flight opportunity and pollen/nectar availability. When both come at the same time, they go to the field en masse. As small nectar sources become available, they can collect a surprising amount if they have a place to put it. Checkerboarding is a leveler for these short spurts because the nectar is stored outside the brood nest, and can be retrieved as required. Under this season’s wretched conditions, strong hives that had been deprived of 3 deep and 3 shallow frames (33% of their normal winter honey ration) only needed a gallon sugar water to tide them over a weak period at the end of March.

We anticipated that as the colony expanded its brood nest into reduced density honey overhead, they might migrate upward with the brood nest. We saw no evidence of this. Spot checks were made periodically and each time brood was solid to the bottom. Earlier, if any empty brood box was on the bottom, it had been moved to the top of the stack. On those with an empty hive body on top, no additional feeding was required – they had more storage space on top.


Last year a recognized expert wrote an article on swarming where he asserted that colonies use swarming as a means of superseding a failing queen. Nothing could be more untrue. The bees would no more condemn their offspring to failure than you would send your first-born child on a mountain climbing expedition with a blind guide. I have seen too many swarm season supersedures of very strong colonies to buy any part of that expert’s opinion on that subject.

To shorten this up some, let’s just say that the strongest colonies I had substituted supersedure for swarming. In the strongest outyard, I mangled prime supersedure cells on five of 12 colonies before I quit lifting the second level boxes. I had wanted to be able to report that I had weathered the swarm season without seeing any swarm cells, but I didn’t want to make then all queenless in order to be able to make that statement!

A double hive body of brood and the most recent hatch-out of that volume can build a showpiece of a supersedure cell. The problem was that a giant supersedure cell on an upper bottom bar is almost invariably attached to the lower top bar. As soon as the upper unit is moved, the replacement queen cell is demolished. In one case where I destroyed both the primary and back-up cells in the same maneuver, I waited two weeks before checking to see what happened. I was pleased to find two of the largest emergency cells ever seen by mankind. I had only handicapped them by a time lag.

Another item of interest occurred at the strong outyard. Two hives had queen troubles in the fall and did not store enough for winter. They were provided two supers each of 50% checkerboarded honey. Toward the end of the buildup period, they both accelerated past the stronger hives at 66% honey, and were the first hives to fill three supers with nectar. While a sample of two is not a very good data base, it does suggest that the empty frames included in the overhead honey could be tailored to accomplish specific goals.

In spite of a disastrous build-up season, I am going into the flow (if there is one) with a minimum of two hive bodies of brood, a couple supers of nectar on the strongest, no hint of an inclination to swarm, and a new queen on the throne. Could it he any better than this?

This concept was formulated to offset the local swarm season triggered by the redbud flow. This year redbud was a wipeout. We got the redbuds, but the purple flowers never opened. So what happens in a “normal” year? It can only get better. Applying these principles will get the hives into the storing mode with more bees at least three weeks earlier. This will take advantage of April sources that rarely show up in the supers. I would wager that I could get March redbud honey in a super.

The checkerboarding concept is so simple and so effective, I wonder how many thousands of beekeepers have taken it to their grave without divulging the secret to their contemporaries?

I stated up front that nectar encroachment on brood volume is the swarm trigger. Go back and reread the test plan. It’s all there. The only thing I could add to the resounding success of the test is the conjecture that the bees have some minimum level of brood volume that they consider mandatory. When nectar availability puts pressure on that minimum volume, they initiate swarm preparations.

I mentioned “unrestricted brood nest expansion” earlier. This is a fringe benefit of checkerboarding, and was not anticipated. While the plan was formulated to offset the effects of one big surge of nectar (redbud), it works as well on lesser sources along the way. The colony that is captive between the lower edge of the brood nest (their hive bottom) and capped honey has to do a juggling act between brood nest expansion and storing any available nectar. When checkerboarded, and nectar is stored above the brood nest, they are free to expand the brood nest at their best rate.

The brood nest expansion proceeds to the two-plus hive body level or the maxi- mum that the queen can produce. We suspect that driving the existing queen to her limits is what triggers the supersedure. If you can tolerate the increased hive height, there is no reason to use a queen excluder. They are raising all the brood they can manage in the brood boxes.

I am not concerned that beekeepers will jump on this scheme and glut the market with honey. They are a stubborn lot. I would guess it will be l0 years before half of them have tried it. If you try it next season on some of your hives, send me 5% commission on the extra yield. I could retire comfortably on that much.


  1. Treat early for mites while the brood volume is less than a hive body of bees.
  2. Verify overwintered colony is queenright.
  3. Checkerboard overhead stores.
  4. Move empty bottom boxes to the top of stores.
  5. Monitor nectar/honey availability at top of the brood nest throughout build-up.
  6. As brood nest approaches 2 hive bodies volume, stay out of the brood boxes.
  7. Maintain 2 supers of empty, drawn comb on top from l-l/2 hive bodies of brood through the lead edge of the flow.