The reasons for why your bees are not filling out their super are numerous and nuanced. Sometimes the answer lies in the timing and sometimes you just have picky bees. Read on to find out all the possibilities as well as some practical tips for how to deal with it.
Bees will only draw out new comb when there is a strong nectar flow. If there’s no nectar to make honey with in the super, there’s no point in wasting energy on building comb that will then sit empty, right? So, if you place a super on your hive during a time of dearth, don’t expect your bees to fill it. Unfortunately, the months on the calendar do not always guarantee that there will be a nectar flow. Sometimes flowers will get started blooming late because of a long winter or sometimes things can dry up early in summer if there wasn’t much rain throughout the year. The best way to determine if there is a flow is to watch your bees. If they are building, bringing pollen and making honey then there’s a flow on! It’s also worth saying that some new or weakened colonies will need to be fed sugar water to get established. This essentially creates an artificial nectar flow which should motivate them to build new comb and increase their population. If you are thinking of feeding, makes sure you read my post: Should I Feed My Bees? before you start.
If you are pretty sure there is a nectar flow happening, but your super is still sitting empty, your problem might lie in how you’ve placed the super. Some beekeepers like to place their suppers at the top where they are more easily accessed and some like to place them at the bottom which plays off the bees’ natural tendency to build downward. Regardless of where I place mine, I almost always move a frame or two of drawn comb with it. This will draw bees to the new box and encourage them to build. I find this especially helpful with foundationless beekeeping. Sometimes, the bees just don’t seem to know what to do with all that new empty space. I have even seen them start to build comb from the bottom of the frame up, like a little pyramid! The added bonus to moving frames up (or down) is that you can place an empty frame in the brood nest, which can keep them from getting honey bound and will keep the bees busy building instead of swarming. Don’t go overboard using this technique to force your bees into the super. If after a few weeks they still aren’t building new comb, you may have been mistaken about that nectar flow. It might be best to move the combs back to where you got them so the colony can cluster properly. This is especially true in late summer.
Foundation vs. Foundationless
On many occasions I have encountered bees that were reluctant to build out comb on foundation. Especially plastic foundation. Instead of trying to convince them to use it, I simply removed the foundation and let them build natural comb. With this obstacle removed, the bees began to draw out comb almost immediately! If you decide to give it a try, make sure you read about comb guides first!
The final thing to consider is the size and strength of your hive. If you have a colony that’s filled all their space, but the population isn’t what it should be, they probably won’t have the resources to fill a super. Before adding a super make sure you have healthy bees! You can gauge their strength by pulling a frame of brood. Your brood frames should be covered in adult bees caring for the larvae, if it isn’t this can be the first sign of a crashing population. You should also check for a healthy brood pattern. A healthy pattern will have a solid swath of capped brood versus the buck shot pattern commonly associated with a number hive maladies. Adding additional space to a weak colony can weaken them further because they will have to defend whatever space you give them and also it can make temperature control more challenging.