What exactly is cross comb? How does it happen? What should I do about it? What’s the big deal? How can I prevent it?
These are typical questions asked by the new beekeeper who has just had their first experience with a mess of cross comb. More often than not, they get this education first hand after ignoring their instructor’s directions about how to avoid cross comb. Well, all learning is valuable, be it in a class room or from a “sticky” firsthand experience. Here’s to hoping you learn and take some of it to heart from this messenger.
But, as we will see, it's more of a problem for you than your bees.
It’s a highly technical term used to describe what happens when bees build comb where the beekeeper doesn’t want it!
OK, so it’s not so technical after all. Beekeepers call it many things, much of which is not repeatable here. But generally speaking, cross comb is built “across” the frames or top bars instead of in the same direction of the frames or top bars of a bee hive. This makes it impossible to remove the frames or top bars without destroying comb, killing bees and generally making a mess.
In the wild, bees locate a cavity they believe will make a suitable home and build their comb exactly the way they see fit. The comb is built from the top down (not horizontally as in a hive) and has passages opened through it making it easier for the bees to pass from one comb to another.
In a tree (or other structure), bees are in charge of their own survival and hive management and the direction of the comb only has to fit their needs.
Bees housed in a bee hive don’t live in a natural environment. Their home is a man-made box, usually made of wood and generally placed in a location the bees would never choose themselves (typically much closer to the ground than they would ever consider and often very close to other bee hives.)
In this artificial, unnatural circumstance created by humans, the bees are not fully in charge of their own survival. In fact sometimes they just get up and leave (abscond) because they do not care for their man-made home and/or location.
As with any creature mankind removes from its natural habitat, the human becomes responsible for the care of that animal and therefore cross comb can become an issue since it prevents the beekeeper from properly caring for and managing their bees.
Sometimes the beekeepers best intentions are ignored by the bees and comb is built perpendicular to the intended direction of the frame or top bar. This happens when the bees find themselves with open space in which to build comb in any direction they want, just like they would in a bee tree in the wild.
Bees tend to build comb in any space greater than 3/8th’s of an inch and fill any space with propolis that is less than 3/8th inch. The 3/8th inch principle is what we call “bee space” and is the space the bees will leave that allows them to move about within the hive.
The easiest way to prevent cross comb is to avoid leaving a large space that allows the bees to build in any direction they want. In the Langstroth hive frames hang parallel and bee space is maintained by confining comb construction to the foundation contained within the frame.
Top bar hives use a single bar across the top of the hive that has an edge on its lower surface to encourage the bees to build parallel combs that follow the orientation of the top bar. Unfortunately, honey bees introduced into a new hive commonly build cross combs that prevent manipulation.
Experienced beekeepers will have seen cross comb at some point and know how to deal with the issues it presents. But for the beginner, cross comb can be very discouraging at the least and a real nightmare at its worst.
Obviously the way to prevent cross comb is to avoid leaving open space for the bees to fill at will. This is easily accomplished in a Langstroth containing frames with foundation, but what about the top bar hive?
Top bar hives are often promoted as requiring less inspection and disturbance of the bees. That may be true for an established colony, but what is often not conveyed to beginners is that they will need to open up and inspect a newly established top bar hive about every three days to cut and correct cross comb as its being built.
After the first season, when the comb has been properly constructed, the existing comb works as a guide that tends to keep the bees building strait comb, one after the other.
Correcting cross comb that has gotten away from the beekeeper is a messy, sticky job that will destroy comb and kill bees - all good reasons not to allow it to happen in the first place.
When beginning a cleanup project of out-of-control cross comb the beekeeper must realize that there will be many smaller pieces of comb that cannot be saved. Your goal is to cut away the largest pieces and re-attach them to the top bar with string and/or rubber bands. This will take patience and the bees are not going to happy with what you are doing. But stay with it and in the long run it will be well worth your time.
Once the comb is reattached to the bars, return them to the hive making sure to keep the frames containing brood together and placing any honey on the outside edge of the brood nest.
The one qualifier on this is that if it’s late in the season when the cross comb is discovered it is best to just let it be. The process of correcting the cross comb can be very destructive and late in the season there won’t be enough time for the bees to secure the comb and recover from the disturbance. The time to go back into the hive and make corrections will be early the following spring when there are far fewer bees to deal with, less brood to damage and plenty of time for the bees to clean up and repair the damage.
I can already hear what you’re thinking – what if I want to go without foundation?
All is not lost. Some simple steps when starting out will help the new beekeeper avoid the problem of cross comb and allow them to avoid the use of foundation.
We’ve already discussed how to avoid cross comb when starting out with a new Top Bar hive. The beekeeper should visit the hive about every three days to correct comb that is not being built in alignment with the bars. But many people also want to go foundationless in their Langstroth hives and there is an easy way to avoid the mess of cross there as well.
In my opinion, in the first year of establishing the hive the beekeeper should use frames with foundation. The bees will generally draw nice straight comb and the beginner will be free to learn all the other lessons that come with the first season of beekeeping.
The following spring the beekeeper can simply remove every other frame of drawn comb and replaces it with a frame that does not contain foundation. The frames with drawn comb will continue to act as a guide and in most cases there will be no cross comb.
If the frames with foundation are marked and the beekeeper wants to remove all frames with foundation he/she can easily do so the following season and replace them with frames that do not have foundation. The bees will use the drawn comb (now containing no foundation) as a guide and build straight comb on the new foundationless frames.
The same principle applies with the top bar hive. Once straight comb has been drawn it will always work as a guide for the straight drawing of new comb on additional bars. The beekeeper simply needs to take the extra step of making sure the comb is drawn straight the first season the hive is put into use.
Cross comb can be very discouraging for a beginner to encounter and yet there are some easy ways to avoid it if some simple directions are followed, as noted above.
If you do encounter cross comb, welcome to the club. It happens to most beekeepers at some point. Take stock of the time of year. If it’s early in the season go ahead and correct the problem. If it’s late in the season wait until early the next spring when your disturbance can be minimized and the bees have all season to repair the damage.
And finally, bring your patience with you when you begin a project to correct cross.