Ask A Master Beekeeper - Impact of a Warm Fall on Feeding the Bees

Q. I have questions about the impact of a warm fall on feeding the bees. I’ve read you need to be careful not to feed when it gets too cold because the bees will have trouble evaporating the honey and moisture may build up. What is too cold?  I did feed in October because there was little food source (after the goldenrod was gone) and the bees were flying, and it was more than a day or two - rather weeks. The bees seemed to have benefited. Used to be the season ended, and it got cold and the bees were inside the hive. Now the season ends, but it stays warm, and the bees are flying and there’s no food. And what about stretches of warm weather in November/December? It’s too late to feed, right? My worry is bees active in all this new warm weather will deplete their honey supply and not make it through until the spring food sources arrive. – Pat from Cobleskill, NY

A. Pat, you’ve asked an excellent question!

You are correct in understanding that late-fall syrup feeding can create problems with excess moisture, particularly if the weather turns sharply colder before the bees can get it evaporated down to a honey-like moisture level.

At the same time, the bees often won’t consume any solid food supplements provided for them this early, either. (Small hive beetles will be happy to oblige by eating winter patty in the fall, but who wants to feed them?)

The best prevention for this is to try and get any syrup that may be needed into the hive earlier in the fall, even if it is commingled with nectar coming in from late-blooming goldenrod and asters. And to do that feeding even at the risk of later discovering you needn’t have fed after all because the flow was unexpectedly strong. As long as the bees have sufficient room to store it, without impacting the final rounds of brood production, they will be happy to have lucked into an extra-bountiful season.

Feeding earlier in the fall flow will also support the natural slowing down of brood production which is not affected by the amount of supplies already in the hive. But the prolonged availability of large quantities of incoming “nectar” can be harmful.

In other words, you want to get any needed supplemental feeding started, and completed, before the natural flow is finally over. It’s best to get any syrup feeding done before the day-time temperatures slip below 60 degrees F. 

Of course, this also means that your honey harvest must be completed earlier. The pattern of waiting to take honey until after you see how the fall flow shapes up is a common problem. Taking the honey off before the late flow allows the bees to keep whatever they can collect afterward on their own, while you can refill any empty frames with syrup, as well.

After the goldenrod was over, if your bees were still flying in a foraging-like pattern, not just in orientation flights, chances are that they were still foraging, even if you saw no evidence of pollen. They were probably robbing out smaller or weaker hives, which to the bees, is just another foraging strategy. (And one that unfortunately, puts them at renewed risk of varroa parasitization from newly-imported mites.) 

If you were weighing the hives throughout the fall, you might be surprised how much they managed to gather from other colonies. We call it robbing, but it can also be thought of as "species-level reallocation of resources."

Unless your hives were nearly empty of all honey/syrup, it's unlikely they are running out of food now, despite the warmer than normal temperatures. Coinciding with the natural seasonal population drop, the honey consumption rate in the late fall and early winter is surprisingly low because the bees do not have to burn the calories required to keep the cluster’s core temperatures high enough to support brood. That will change, of course, in midwinter when brood raising begins again in earnest. So, while they may still have adequate stores for their current needs, that doesn’t guarantee they won’t run out before new supplies can be located next spring.

Once the hives are at good wintering weights, your next task is to make sure they are remaining that way. The easiest way to confirm that is by checking total hive weight from time to time. A colony that’s sharply losing weight needs attention and certainly plans should be made to provide for supplementary solid food during the winter.

If you didn’t get the syrup on early enough for it to be dried down and stored with the honey, then I would wait and offer solid food (sugar bricks, commercial winter patty, or even loose granulated sugar) sometime after mid-December and plan on keeping it regularly replenished all winter long, until dandelions are in bloom again. In winter weather the bees will happily eat solid food.

The extra effort required to provide even just maintenance calories for a single hive is enough to motivate one to feed early, and generously, in the fall. One year in the middle of winter, I discovered a friend's hive that was literally completely dry, with no honey or stored syrup at all. I fed it winter patty all winter long, and it made it through. But it took a lot of attention and work to constantly balance the potential downside of repeated cold-weather hive openings against the urgent need for fresh calories in order to survive. Those bees ate more than 60 pounds of winter patty before winter was done.

If you want to read more about how to assess a colony for winter stores (in cold-winter areas) and how to feed, you could check out the October 2018 and the January 2019 Newsletters. The December 2018 issue has information about making home-made sugar bricks. Click here to go to the Newsletter Archives.  I try to slide some sugar bricks into every hive in late December both as insurance and as a welcome-to-the-top-box snack when they arrive there from the lower boxes.

My thanks to Pat for allowing me to use her question for the inauguration of the Ask a Master Beekeeper column. Next month, it could be your question here. So, be sure to send your question in as soon as possible.

Nancy