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Overwintering Nucs

By N.J. Gates

To overwinter nucleus colonies successfully you must make sure all the basic requirements for full size colonies are looked after. In other words the colonies must be disease free, treated to control mites, should have adequate good quality feed, be populated by healthy young bees and be headed by young prolific queens of winter hardy stock. In addition these units must have extra winter protection.

When fall feeding thick syrup add fumigillin for nosema control. Nosema is a stress related disease that nucs are susceptible to because of their small size. Nosema also compounds the effects of mites. The combination is a real nuc killer.

Any syrup feeding should be done in September to give the bees time to properly ripen and store it under wax. Improperly cured stores will ferment and may cause problems with dysentery.

When I began to experiment with nuc overwintering I had trouble consistently getting anything less than about 8 frames of bees through winter. Now, even 3 frame nucs seem to be no problem. Although I have refined the process over the years I believe that a lot of the success is due to using winter hardy stock developed for this area.

Since I have been selecting for winter hardiness (colonies that come through winter with relatively large populations and plenty of unused stores) my success has increased. If you want to winter nucs you should consider producing your own selected stock. If not you should at least buy queens with stock of proven wintering ability, preferably from a local producer.

Young bees are crucial for overwintering. Old bees worn out by summer foraging will not survive the winter. In this region, nucs confined to a small area like a 4 or 5 frame nuc box often plug out with honey in the latter part of the season. This leaves little egg laying room for the queen resulting in an inadequate population of young bees for winter, although the population over all may look good because of the presence of old summer bees.

When producing 4 or 5 frame nucs to winter I used to try to make them up some time in the summer with just enough bees and brood to develop into units that would completely fill their boxes with young bees but also enough stores (at least 3 full frames for winter). I found that to be very difficult, varying tremendously with the season.

Now I start my nucs out in standard deep boxes divided in two, making 2 four or 5 frame compartments. As the season progresses, if the nucs look as though they will outgrow their spaces I transfer them to full-size standard boxes on standard bottoms or special inner covers with entrances used as bottoms. This provides the queens with plenty of room for egg laying to produce lots of winter bees, at the same time allowing lots of space for stores.

I don't necessarily fill the boxes with frames, just giving them what they need including a frame feeder. Most of these nucs grow to cover 6 frames. Some surprise me by developing into a full box of bees. In a four or five frame compartment they would have filled their boxes and stagnated.

If I have made some of the units so small that they just fill their compartments in the split boxes by the end of the season that's fine. I leave them where they are.

They are a problem to feed though if I can't get a frame feeder in. Then I use special inner covers to keep the nucs separate but with 2 feed holes. If I were to build the nuc boxes again I would build frame feeders that also function as moveable dividers separating one nuc from another in the standard deep box while at the same time allowing both nucs access to syrup. This design is described by Kirk Webster and has also been used successfully for years in Kelowna by Bill Ruzicka.  When the nucs outgrow their compartments, one can be moved out to another box while the other can remain where it is with the feeder moved over and extra combs added.

For winter protection I place the nucs that are in full-size boxes on top of large (2 deep boxes) hives, separated from the colonies below by modified inner covers that have no feed hole and a rim on both sides of the plywood with a swivel entrance in one rim. These are the inner covers sometimes used as bottom boards.

The rims allow bee space over the top bars of the hives below and beneath the bottom bars of the nucs above. The solid, thin plywood prevents stale moist air from rising into the nuc above but still allows heat to transfer from below. The bottoms of the double compartment nuc boxes are constructed exactly the same but are fastened permanently to the boxes.

All of the nucs are provided with upper entrances but no lower ones. My hives are kept 4 to a pallet, two facing east and two west. For winter they are shoved together so that the boxes touch and the nucs are placed on top, also facing east and west. If the nuc colonies onlycover 6 or 7 frames I slide them over to the side of their box which touches their neighbour's box. The frame feeder is then moved against the outside frame of bees leaving an unoccupied space in the box.

In the spring I then have room to add frames of honey if necessary. Each nuc is topped by a piece of carpeting with 1 inch blue styrofoam above. I wrap the whole grouping with black building paper around the perimeter, folded over the top like a parcel. The whole thing is topped with a sheet of plywood or tarpaper held down by a couple of lids. I cut holes in the tarpaper opposite the upper entrance auger holes in the nucs and big colonies below. Everything is then warm, and waterproof.

Years ago in trials we found that the big colonies didn't necessarily benefit from the wrapping but the nucs definitely did, consuming less feed and losing fewer bees. Since the colonies below can't easily be inspected or fed in late winter or early spring I make sure they are well fed in the fall so that no early feeding is necessary. I find that makes for better survival anyway because in previous years I sometimes relied on late winter feeding but lost some colonies to starvation.

Usually the nucs go on top of the hives in late October or early November. By then there is little bee flight, so even if the nucs were already located in the same yard there is no problem with drifting. But drifting can be a real problem in spring. No matter how well marked the boxes and entrances, I find an unacceptable amount of drifting occurs between nucs and big hives after the bees are flying regularly.

This results in some huge hives and almost beeless nucs or sometimes the other way around. To avoid drifting I remove the nucs usually in late March placing them on top of old junk empty boxes to keep them off the cold ground. Although the nucs would benefit from the warmth of the colonies below this is more than offset by the drifting problem. I don't think it would be as much of a problem if my hives were kept 2 to a pallet with the nuc entrances facing the back of the hives.

In late winter/early spring I check a few nucs in each yard. To do this I remove the outer top covering then slit the building paper with an exacto knife in a line even with the top of the insulation. I discard the paper that was wrapped over the top.

Any nucs that need feeding get frames of honey I have saved from the previous season. I scrape off some of the cappings and position them against the outside of the cluster. One beekeeper I know feeds extracted, granulated honey to his nucs. I don't like to feed syrup to nucs (particularly small ones) too early in the spring because I think it stresses them unduly.

Well that's about it for wintering nucs. If this article has you interested but you find yourself nucless you may still have time to make up a few to try, but first see if you can find some winter hardy young mated queens. Break apart a hive that still has large frames of brood and make up nucs that consist of at least 2 big frames of brood, three full frames of honey and 4 frames in total completely covered with bees and the young queen. If you can't find the proper ingredients wait till next year.

Good luck!