When to feed... Apart from which hemisphere you keep bees in, there are differences in natural pollen and nectar sources that will modify the dates locally. There are considerable differences in attitude, beekeeper to beekeeper. I have generally fed bees later in the season than most, I have not noticed any ill effects from this (this does not mean that my bees have never suffered from dysentery) but that I have been unable to ascribe late feeding as the cause.
I myself stopped feeding for winter as a matter of routine in the late 1980s and have sometimes left a partially empty shallow super to receive any ivy honey and provide a reserve that the bees can use or ignore according to their needs. I commonly winter in only one National sized brood box, and providing they store 15 or so kilos of honey I will not feed further.
What to feed... Some beekeepers feed only honey and others feed mostly sugar syrup. There is no right and wrong, because it depends on what race of bee is being considered and their suitability for the conditions that they are being wintered in.
"Normal" nectar is mainly sucrose and water and as it is concentrated by evaporation, the bees add enzymes that invert the sucrose into mainly levulose and dextrose, with a small amount of sucrose left uninverted. The concentration of the resulting honey is so strong that it does not support mould growth.
When bees pack away sugar syrup it is already fairly concentrated and their opportunity to add enzymes is limited, but a small amount of inversion does actually take place.
The difference between stored honey and stored syrup is the ratios of the sugars in the mixture and that stored syrup contains much lower numbers of pollen grains and a smaller amount of the other minor constituents of honey.
Bees that are adapted well to the conditions that they find themselves in can cope alright with the pollen (protein) and as a result they winter OK on honey.
Bees that are not well suited to their wintering conditions tend to suffer from dysentery as the build up of pollen husks causes them to void within the hive. (This could aggravate nosema disease if present. R.P.) If these bees are fed syrup instead of honey they are better able to survive wintering in the conditions concerned.
There is a further complication in that bees consuming stores consisting of mainly sugar syrup lose body fat in the process of assimilating the sugar. Depending on whether this fits or not with the weather pattern and spring development of the type of bee, this may or may not be a "problem". As an example... Many Italianised strains of bee that are kept to the south of where I live (the UK midlands), will suffer far fewer losses when wintered on syrup than they would if they have only honey stores. My local "more native" bees are well adapted and manage perfectly well on honey (which is mainly what they get).
How much to feed... This is another factor that is dependant on the race of bee being considered. In my area my bees manage with 13kg - 15kg of honey, yet a few miles away another beekeeper with Italianised hybrid bees will feed his colonies until they weigh 40kg or even more. In really cold conditions in Canada I have heard of weights of 70kg being required. From these wide variations it is obvious that you have to get to know your area and prevailing conditions by asking other beekeepers, in your locality, what, and how much, they expect to feed.
What feeder to use... I favour overall wooden feeders that are the same size as the hive that they are intended to fit. I find no difference between Miller, Ashforth and Bro. Adam types or any of the many variants.
I dislike the advice given that you need "X" kg of stores per colony to winter them. This doesn't take into account the type of bee, the size of the colony, the length of the winter or the part of the country. Yet again, I think it's simply one writer copying another. A colony of Italians in the south of England is going to need far more than a colony of native Amm bees in the north of Scotland.
I have seen it written that Italians need 2.5 x the amount of food during a year as native or native type bees and I wouldn't argue with that for the winter.
My bees are on a single brood box national all year and there is usually a reasonable amount of stores in it at all times. Very often I don't feed, but if I do, I tend to give it in small amounts to get the queen laying, then feed until they won't take any more. I find that if you feed too much at once the queen hasn't got chance to lay up a reasonable sized brood area before she is crowded out with food.
I have always felt the best way to feed bees is to chug off down the garden every other night with a jug of syrup. This keeps the queen laying that provides winter bees and as there is a regular supply of food, the bees can cap what they have already been given.
I don't like feeding additives prophylactically because I think it masks the fact the bees may be susceptible to disease. I think there may now be a case for feeding thymolised syrup, at perhaps 3x Manley strength, to help reduce mould growth and fermentation. Now we have varroa to deal with and the treatment often disrupts feeding we are feeding later than I would like, so thymolised syrup may be a benefit.
Apart from the odd occasion when I have needed to do it, I haven't left a super of honey. There is no reason for this apart from the fact I can sell all the honey I can produce 5 times over. I think for the amateur beekeeper there is a lot to be said for it. I used to advise taking the queen excluder out to prevent the bees going through the excluder and leaving the queen behind, but I spoke to a very good beekeeper of over 30 years experience with 50 colonies who winters on a super, leaving the excluder in and he has never lost a queen.
Peter Edwards of Stratford-upon-Avon is a commercial beekeeper who successfully feeds fondant in the autumn. See the button top left