How much sugar to feed bees for winter
The amount depends on how much honey the hive already has. Enter that and the honey you want it to have going into winter. The page turns the difference into pounds of sugar, gallons of 2:1 syrup and 25 lb bags. If you don't know what the hive holds, the winter honey stores calculator estimates it from your frames.
How the number is worked out
The University of Arizona Extension publication az2014 says one gallon of 2:1 syrup (2 parts sugar to 1 part water) can add seven pounds to a colony's food reserves. A gallon of 2:1 by weight takes about 7.4 lb of sugar, so the calculator uses 1.05 lb of sugar for each pound of stores to add. Treat it as an estimate and weigh the hive again after feeding.
The gallons are the finished syrup, mixed by weight. Some extension pages give heavy syrup as 16–17 lb of sugar per gallon of water, which is a different gallon: it counts only the water. Per gallon of water, 2:1 by weight takes 16.7 lb of sugar; per gallon of finished syrup it takes 7.38 lb, because the dissolved sugar adds volume. Mixed by volume, 2:1 is a thinner syrup, and the same sugar makes more of it. The syrup calculator shows both.
Common gaps
Sugar and 2:1 syrup for a gap of 10 to 40 lb of stores.
| Stores to add | Sugar | 2:1 syrup | 25 lb bags |
|---|---|---|---|
| 10 lb | 10.5 lb (4.8 kg) | 1.4 gal | 0.4 |
| 20 lb | 21.0 lb (9.5 kg) | 2.9 gal | 0.8 |
| 30 lb | 31.5 lb (14.3 kg) | 4.3 gal | 1.3 |
| 40 lb | 42.0 lb (19.1 kg) | 5.7 gal | 1.7 |
When to feed, and with what
UF/IFAS Extension says winter preparation must begin in late summer or early fall, usually August or September in northern climates, and that bees store the syrup as a substitute for honey. Its mix is 2 parts sugar to 1 part water by volume. My suggestion, not from these sources: feed early, so the bees have time to carry the syrup down and reduce it before the nights get cold.
Once it is too cold for bees to take syrup, the Arizona publication says dry granulated sugar can serve as an emergency food in late winter or early spring, to prevent starvation. It gives no amount. The candy board calculator scales two published sugar and water mixes to your boards.
Have the amount and want the calendar? How long to feed syrup in fall turns it into feeder refills, feeding days and a finish date.
Checking the weight
UF/IFAS describes a lift test: lift the back handle of the bottom box with one hand. If the hive is hard to rock forward, it likely has enough food. If it lifts easily, it probably needs more.
For a number, The Apiarist weighs hives by lifting each side a few centimeters with a luggage scale and doubling the reading, and found that this method read about 8% under the true weight. It puts a colony's use at about 1 kg (2.2 lb) a week in maintenance mode, rising once brood rearing starts, and advises repeating the weight check every 2 to 3 weeks. At 2.2 lb a week, a 10 lb gap is a bit under five weeks of food, so check again after feeding.
Total hive weight includes the boxes, frames and bees, so it is more than the honey alone; the hive weight page subtracts the empty hive and the bees. The honey targets are in the table on the stores page.