Autumn Feeding: Syrup Ratios, Timing, and How Much Is Enough

Autumn feeding is the last major management decision of the beekeeping year, and it is unforgiving. Get the quantity, concentration, and timing right and your colonies go into winter with a full pantry. Get any one of them wrong and you find a dead cluster on empty comb in late winter — often within centimetres of stores it could not reach.

Why 2:1 Syrup in Autumn

Spring feeding uses thin 1:1 syrup (one part sugar to one part water by weight), which mimics a nectar flow and stimulates brood rearing. That is exactly what you do not want in autumn.

Autumn feeding uses thick 2:1 syrup — two parts sugar to one part water by weight. The reasoning is simple: the bees have to evaporate the water content down before capping. Thicker syrup means less water to remove, less energy spent, and faster storage. In cool autumn weather, colonies fed thin syrup often cannot cure it in time, and uncured syrup ferments in the comb.

Use plain white granulated sugar. Never feed raw sugar, brown sugar, molasses, or anything containing plant solids — the indigestible residues cause dysentery in bees that cannot take cleansing flights for weeks at a time.

How Much Does a Colony Need?

Target overwintering stores depend heavily on climate:

• Mild temperate winters: 15–18 kg of stores
• Cold continental winters: 20–25 kg of stores
• Long, severe winters: up to 30 kg

Weigh or heft the hive first. Every litre of 2:1 syrup fed converts to roughly 0.75 kg of stored honey-equivalent once cured. So a colony 8 kg short needs roughly 11 litres of syrup — not one small feeder top-up.

Timing Matters More Than Quantity

The critical constraint is temperature. Bees need daytime temperatures reliably above about 10 °C to take down and process syrup efficiently. Once nights turn cold and the cluster tightens, feeding effectively stops working.

Work backwards from your first hard frosts and aim to have all feeding finished four to six weeks before them. In most temperate regions that means starting in early September and being done by mid-October.

Feed Fast, Not Slowly

A common mistake is dribbling small amounts of syrup into the hive over many weeks. This mimics a light nectar flow and stimulates the queen to keep laying, producing late brood that consumes stores and shortens the life of your winter bees.

Better: feed large volumes in a small number of sessions using a rapid or contact feeder that holds several litres. The colony stores it as bulk provisions rather than treating it as a flow.

Watch for Robbing

Autumn is peak robbing season. Feeding sets off scent cues that draw robbers from every hive within range. Protect yourself:

• Reduce entrances on weak colonies before you start feeding.
• Feed at dusk, not midday.
• Never spill syrup on the outside of hives or in the apiary.
• Feed the whole apiary at once, so no single hive becomes a target.

Fondant Is the Winter Fallback

Once temperatures drop, syrup is no longer an option. If a colony is light in midwinter, place a slab of fondant directly over the cluster on the crown board hole. Bees can use it at cluster temperature, and it adds no moisture to the hive.

Fondant is emergency intervention, not a plan. A colony that needs fondant in January was under-fed in September.

Record Everything

Log feed type, concentration, volume, and date for each hive. Come spring, the colonies that came through strongest tell you what your local target really should be — and next autumn you feed to that number instead of guessing. Tracking feed alongside hive weight and winter survival in ApiaryPilot turns a yearly guess into a repeatable protocol.