Depending on what strain of bee you have the amount of stores needed by your bees to get through winter will vary. We can apply an average rule that your bees will need somewhere around 18-22kg (40-50lb) to get them through winter, some large colonies headed with prolific queens may use more.
When we harvest the honey off our bees at the end of August we need to ensure we leave enough for our bees. If you run nationals, and you have strong colonies that you have removed all the honey supers from it is very unlikely your bees will have enough space in the brood box to cater for all the stores needed for winter. Remember that your colony will still have quite a bit of brood, especially if they are strong so there will be limited food in the brood box, although the brood nest will be reducing their may not be enough foraging time available for them to fill the hatching brood cells. For this reason it is common practice for those who run nationals to leave their bees a super of honey. The super is usually put under the brood box rather then left on top. The reason for putting it underneath is that when the queen starts to lay, she will most likely lay in the middle and work upwards and therefore when you do your first spring checks you may find that you have brood in your super. If you put the super underneath it is very unlikely that you will have any brood laid in it. When you do your first winter checks you simply rotate the boxes back around and reinstate the queen excluder between them (you will have removed the queen excluder to allow the cluster of bees to move freely around both boxes during the winter months) making of sure that the queen is in the brood box! It is said that a full national super of honey can hold anything between 25 – 40lb of honey. This will of course depend on how your bees have pulled the frames, how full the frames actually are and how many frames you have in your super e.g. are you using dummy boards in your super! But, in any case above if the super appears full and has a good weight to it you will have a substantial amount of honey stores, which in addition to the honey stores they can get into the national brood box, should equate to a good amount they will require for winter.
A British Standard Brood frame full of honey contains around 2.2kg (5lb) of stores. A 14×12 brood frame holds around 3.25kg (7lb). Both Commercial Brood and Langstroth Brood Frames holds around 3kg (6.5lb), the commercial holds just a little more than the langstroth. Using these figures you can assess the amount of stores in your colony and if they are short of stores you can offer you bees some syrup to top them up.
Most beekeepers would offer them a syrup feed, this can be a pre-made bee feed or you can mix your own sugar feed. Syrup can be offered to the bees in various different feeders; rapid feeder – these are placed on the crown board and the bees have access from below by means of hole or slot and a barrier which prevents them from drowning. There are many varieties of rapid feeders, some only take small amounts of feed and others can take large volumes and they are known by different names but all function in the same way – Ashforth, Miller, English, these all take larger volumes of syrup. Contact feeders are plastic buckets with a gauze cover hole in the lid. You need to invert these to create vacuum so you do need a bucket or something to catch the syrup that will come out before the vacuum holds it, the bucket is then positioned, with the gauze directly over the hole of the crownboard. Frame feeders are another type of feeder however you will need to remove at least one frame to make space for the feeder so I would suggest that a frame feeder would not be a good choice if you were trying to get the maximum amount of stores into your bees as the season is drawing to a close, these would perhaps be better used during the season if you find you need to feed during a dearth.
I do know of a few beekeepers who say they only ever offer their bees fondant no matter the time of the year. There is some question as to whether the bees do take fondant down into the brood nest and store it or if they only use it when they need it so do bare this in mind if you are feeding your bees to encourage them to take down stores. We have always only fed fondant over the winter months and syrup at any other times. Certainly if you came across a colony that was on the verge of starvation you would need to offer them syrup. We do cover what to feed bees and when in another post.
How do we check if our bees still have food in the middle of winter?
As we go through winter it is simply not good enough to think your bees will have enough stores, you must check them, if you don’t and they run out of food they will die of starvation. “But we don’t open our hives in the winter so how do we check?” I hear you ask. How we check for stores is by hefting. You heft your hive on three sides and see how heavy it is. We check on three sides because if the food was all stored to one side and we only hefted from the back we would not feel the weight so by checking three sides we will get a better estimate of whether they need extra feed or not.
I always suggest to new beekeepers that they heft their hives during the season after an inspection so they can get a feel for the weight. You will know how many frames you have filled with food, so if you heft it once you have put the roof back on and you will start to get an idea of what weight relates to what food stores they have so when winter comes you will be better prepared.
If you find your hives are feeling light then you can offer them fondant. You cut a hole in the underside of the fondant pack, peel back the wrapper to expose it and place this directly over the hole of the crownboard, your bees only have to come to the underside of the hole to get the feed. The wrapper is see through so to check if they need more all you need to do is remove the hive roof, which can be done quietly and quickly thus not disturbing the bees.
If you have done all of the above then you can feel assured you have done all you could for you bees. Unfortunately there will always be winter losses and even if your bees do have food stores either in the frames or fondant on the crownboard they may fall victim of starvation. Winter starvation where they have food stores is usually down the bees, when in cluster during very cold periods, moving away from the food and not with it. The diagnosis for death in this case is called isolation starvation and there if nothing you or anyone could have done to foresee this happening or indeed to help.