Wintering 5 frame Nucs

During the winter of 2011 - 2012 we experimented wintering 16 five frame nucs. Several beekeepers were wintering nucs indoors, so it seemed to make sense that we should try it outdoors. Our purpose was to see if we could bring more queens through the winter on regular combs with which to requeen hives in the spring. We hoped it would also make up our numbers quicker.

We wrapped them in packs of eight. All 16 came through the winter, but 2 were weak and soon died. However, since it was a warm winter with almost no snow we questioned whether the results were repeatable.

Therefore, in the fall of 2012, we put 57 five frame nucs into winter. They were wrapped in packs of 7 or 8. Fifty-four came through the winter. They were covered with snow almost immediately and remained covered until spring. We decided to do stimulus feeding of them before they could fly. We put 250 ml of syrup in a Ziploc bag with top slits in the top of the nucs. We also treated them with oxalic drizzle. Through this action we killed another 15 of them. (The lids squeezed some of the syrup out of the Ziploc bags on to the bees.)

In the fall of 2013 we prepared 138 five frame nucs to winter in two beeyards, in packs of 7 or 8 with top entries. They were covered with snow almost immediately, and remained covered until spring. We also kept track of the dates that the nucs were started to see if losses in the spring would correspond to that how early or late they were started. In the spring of 2014, only 21 were alive and there was no correlation to when the nuc was started to the death rate. The winter was long and the surviving nucs looked hungry. We could not identify anything that we had done different from the previous years and yet most had not survived. Was it weather related, or is there some other factor that we have not accounted for?

However, the initial results wintering 5 frame nucs still looked promising so, we prepared 213 - 5 frame nucs for the winter of 2014 trying to make up our previous losses. They were fed sugar syrup and then 190 were wrapped in packs of 7-8 nucs in three beeyards. 23 were wintered indoors as a small sample to see if that might work better. This time only 70% had top entries since some emerging information seems to indicate that smaller colonies do not require an extra top entrance for ventilation and in fact the top entrance harms them because of the extra ventilation. Those indoors were stacked in 3 layers of 7 or 8. Four nucs were placed side by side facing another four nucs with about 30 cms between the front entrances of the two rows. Then the whole bunch was packed with some insulation with air vents so that the temperature of the pack could be monitored and controlled. This time we tracked where the nucs were started and fed as well as the date they were started.

In the spring of 2015, 113 of the 213 - 5 frame nucs were still alive meaning 47% had died. The survival rate in the outdoor wintered nucs (54%) was higher than the indoor wintered nucs (39%). Of the 30% being wintered outdoors with no top entrance, only 14% survived, whereas 69% of the nucs with top entrances wintered outdoors survived. There was no correlation between where the nucs were started and fed to their survival rate. The quality of the queens could also not be blamed for the losses during the 2014-2015 winter. The survival rate of those wintered outdoors still seemed successful enough to merit more study.

In 2015, we hypothesized that the type of feeder made a difference to their wintering success. Was it possible that those nucs that took the feed down quickly and shut off brood rearing wintered better than those whose feed trickled in at a slower rate due to the type of feeder? Was the slow feed stimulating the nucs to continue brood rearing and therefore not winter as well? To see whether it was the preparation of the nucs rather than the conditions that they were wintered in, we needed to again compare outdoor wintered nucs to indoor wintered nucs. This time we prepared 89 five frame nucs for winter. We put 41 into the indoor facility and 48 with top entrances to be wintered outdoors. We tracked the types of feeders that they were fed with, ensuring that some of each went both indoors and outdoors. In the spring of 2016, we lost 15% of the outdoor wintered nucs and 10% of the indoor wintered nucs. That is an acceptable winter loss indicating no problems. There was no correlation between the type of feeders they were fed with and the dead nucs.

We had assumed that five frame nuc colonies were too small to winter outdoors. Clearly, we were wrong. We no longer thought it was so much the size of the colony or how much feed they had access to, but instead how well they filled their home. We know that several people in a room can heat that room requiring little outside energy. Comparatively, a few people in a large house requires a lot of outside energy to heat it. We just hadn't transferred that knowledge of energy to our beekeeping. So, a colony in smaller space uses less feed providing that it fills that space.