Sugar syrup for bees: 1:1 or 2:1, how to mix it, and when to feed

Most beekeepers feed sugar syrup at some point, and most of the harm done by feeding comes from a handful of avoidable mistakes: the wrong sugar, the wrong ratio for the season, feeding with honey supers on, or feeding in a way that sets every bee in the apiary robbing. None of it is complicated. Here is which sugar to use, how to mix the two standard ratios, when each one is fed, and how to get it into the hive without trouble.

Which sugar

Plain white granulated sugar, from cane or beet, is what bees can digest safely. Everything else carries a risk. Brown sugar, raw sugar and molasses contain solids that bees cannot digest and that can give them dysentery when they are confined in winter. Icing sugar often contains starch to stop it caking. Honey from anyone else's hives, even your own from another apiary, can carry the spores of American foulbrood, so it is never fed back to bees unless it came from the same healthy colony. Commercial beekeepers also use ready-made bee feed syrups, which are formulated for bees; syrups made for people are not the same thing.

How to mix 1:1 and 2:1

Ratios are simplest by weight, and weighing is more accurate than measuring by volume:

• 1:1 syrup: one kilo of sugar dissolved in one litre of water, or one pound of sugar to one pint of water.
• 2:1 syrup: two kilos of sugar dissolved in one litre of water, or two pounds of sugar to one pint.

Measured by volume, a cup of sugar to a cup of water, the syrup comes out a little thinner than by weight, and the bees cope with that. Use warm or hot water from the tap or kettle and stir until the syrup is clear, with no grains at the bottom. Do not boil it: heating sugar hard, especially with lemon juice or vinegar added, produces HMF, which is toxic to bees. Nothing needs to be added. Let it cool to lukewarm before it goes on the hive.

When to feed 1:1

Thin syrup looks like nectar to the bees, and they respond to it as they would to a flow: the queen lays more and the workers draw comb. That makes it the feed for spring and early summer, when a colony needs to build, for a new nucleus or package with foundation to draw, for a colony that is short of stores after winter, and for a dearth, a spell with no forage, in the middle of the season. It is not a feed for autumn, because it stimulates brood rearing when the colony should be slowing down, and it carries more water than the bees can easily remove in cooling weather.

When to feed 2:1

Thick syrup is for stores. Bees take it down quickly and have less water to evaporate before they cap it, which is exactly what is needed in autumn. Start as soon as the honey supers are off and the late-summer varroa treatment allows, and aim to finish while the days are still warm enough for the bees to process and seal it; syrup taken down too late stays wet in the comb and can ferment. How much honey bees need for winter gives the target to feed to. Once it is too cold for the bees to work syrup, switch to fondant placed directly over the cluster.

Which feeder

• Contact feeders, a bucket or jar with a mesh lid turned upside down over the hole in the crown board, deliver syrup slowly, reach bees even in cooler weather, and are the least likely to start robbing.
• Tray or rapid feeders, which sit on top of the brood box under the roof, hold large volumes and suit autumn feeding, when a colony needs several kilos quickly.
• Frame feeders replace a frame inside the box. They keep the syrup close to the cluster, but the hive has to be opened to fill them and bees can drown in them without a float.
• Entrance feeders, which hang a jar at the front of the hive, are the easiest to check and the most likely to attract robbers. They are best avoided.

Feeding without robbing

Robbing starts when bees from other colonies, or wasps, find sugar they did not have to forage for, and a robbing frenzy can kill a weak colony in an afternoon. Feed inside the hive, never in an open container in the apiary. Feed in the evening, when foraging has stopped and the smell has settled by morning. Do not spill syrup on the outside of the hive or the ground, and wipe up any that does spill. Reduce the entrances of every colony while feeding, and feed all the colonies in the apiary on the same evening, so none is singled out as a target.

Mistakes that cost colonies

• Feeding with honey supers on. Syrup is stored as honey and ends up in the harvest. Take the supers off first, or do not feed.
• Feeding thin syrup in autumn, or thick syrup so late that it is never capped.
• Feeding a colony that does not need it. In spring, a colony fed heavily while it already has stores can fill the brood nest with syrup, leaving the queen nowhere to lay and pushing the colony towards swarming. Feeding is a decision, not a date covers how to tell.
• Stale syrup. Mix what the bees will take in a few days and throw away anything that smells sour.

Write the feed down

Record each feed against the hive or apiary it went to: the date, the ratio and the amount. Over a season those notes show which colonies needed feeding and which never did, which is a better guide to requeening and site choice than any single inspection, and they are the input to what each hive really costs. The feeding records in BeehiveMind take one feed for a single hive or a whole apiary at once.