When to stop feeding bees in fall
Liquid syrup has a cutoff, and the two sources I found put it at different temperatures. Oregon State University Extension says to stop once daytime temperatures drop below 57°F. The Honey Bee Health Coalition says to finish before it gets below 50°F. Enter your daytime high to see where it falls against both.
What each source says
| Source | Cutoff | What to do |
|---|---|---|
| OSU Extension | 57°F (13.9°C), daytime | Stop liquid syrup, switch to a solid sugar board |
| Honey Bee Health Coalition | 50°F (10°C) | Complete syrup feeding before it gets below this |
The OSU answer is by Anna Ashby, a Master Beekeeper volunteer with OSU Extension in Yamhill County (published November 2019, reviewed 2024). Her reason is moisture: liquid syrup puts too much of it into the colony, and the bees can't evaporate the excess for long-term storage. She notes that the Coalition suggests stopping at 50°F during the day.
The Coalition's Best Management Practices for Hive Health (page 72) says fall feeding can begin as soon as the supers come off and should be completed before the temperature gets below 50°F, because bees stop taking down syrup once it gets too cold. It does not say whether that is air, syrup or day or night, so I read the two figures as a range. OSU reads it as a daytime figure.
Honey Bee Suite explains the mechanism: in cold weather the bees can't dehydrate the syrup to the roughly 17% moisture that is suitable for capping. It also says to remove leftover syrup promptly once the bees stop taking it. In a 2013 reply to a reader, the site's author says bees can drink syrup until the syrup itself drops to about 50°F. It is a comment below the article, so treat it as a hint to check the feeder.
How much to get in before the cutoff
The Coalition guide says each colony should be fed 4 gallons (15 L) of 2:1 syrup in the fall. That guide mixes by weight. Four gallons of 2:1 by weight is about 29.5 lb of sugar and 14.8 lb of water. The syrup calculator shows the same amounts in cups and liters.
That is a general figure. A hive that already holds most of its winter honey needs less, and the stores calculator or the hive weight page shows whether yours does. UF/IFAS Extension says fall preparation of colonies usually starts in August or September in northern climates. Its syrup recipe is 2:1 by volume, while the math above follows the Coalition's by weight. My suggestion, not from these sources: plan the feeding backwards from your first cold week, so the last gallon goes in while the highs are still above the line you picked.
After the cutoff
The Coalition guide lists dry sugar and fondant as recommended when syrup isn't an option, for example in the dormant phase. It also warns that bees need water to dissolve dry sugar, that they may ignore it or carry it out of the entrance, and that they don't normally store it, only eat it. It calls these feeds, at best, temporary solutions for colonies with low stores that are in danger of starving. It gives no amounts, and I found no extension figure for a sugar brick per hive, so this page has none either. For a solid sugar board, the candy board calculator scales two published mixes.