As tempting as it is to wait and see if you can get enough natural boost from the fall flow, in most places it’s better to start any needed feeding at about the midpoint of the flow, or even earlier. As soon as your honey supers are off (if you still had them on at the end of the summer) is a good starting point to assess the stores and begin feeding, if necessary. It’s okay if the bees mix syrup and late season honey in their winter stores – they will eat it all up by spring.
If you wait until after the fall flow is over you may have problems with feeding due to low temperatures at night. Bees won’t readily take syrup that is below 50 degrees F, and if it cools off at night, it may not warm up enough again during the next day to make it palatable.
If you’re feeding after all the other forage is gone, you will ramp up the risk of robbing because your hives will be the only remaining resource for other colonies’ foragers. It’s better to get the feeding done when bees are still actively foraging.
But if you still need to feed, even if you’re a bit late, give it a shot anyway. Any syrup you can get the bees to take now will reduce the need to provide supplemental food during the winter and early spring.
In the fall, the syrup mix is 2:1 (sugar to water, by weight). Fall syrup is more concentrated than the 1:1 syrup that is usually fed in the spring. Making it more concentrated reduces the energy cost to the bees to dry it down to honey-like consistency, and also reduces excess moisture in the hive, which can be a problem in the fall.
Use only granulated cane or beet sugar when making syrup for bees, never powdered sugar, brown sugar, or organic sugars that may contain indigestible particles. Do not allow it to overheat and caramelize. Although heat makes the heavy syrup mix easily, do not cook the syrup.
Recipes for making 2:1 syrup:
Use water that is at least 140 degrees F. Don’t use boiling water – let it cool slightly as you carry it from the stove to the mixing area. Do not cook the syrup – add the hot water to the sugar.
If you have them, surplus frames of capped honey are the easiest way to add stores to a hive with a shortage. Use them to replace undrawn foundation. Empty drawn comb can be added to a colony that needs additional space to store syrup.
The best feeders during the fall are those that are entirely inside the hive, either frame feeders or top feeders. This helps keep robbing under control. Top feeders are also the easiest to refill without opening the hive, something that also helps prevent robbing.
When filling feeders, take care not to spill syrup, as that would encourage robbing. Dilute or wipe off spills on the ground or on the sides of the hives.
Keep track of how much syrup you provide to each hive so you will know when you’ve reached your target.
If you have problems with mold in the feeder, remove the feeder. Wash it in hot water and rinse with a little bleach water. To help prevent mold, add one teaspoon per gallon of apple cider vinegar to the next batch. To keep mold from forming on the undersurface of your telescoping cover, install a 1” or 1.5” thick piece of foam insulation up inside the cover. (That will also give you a jump on winter prep.)
If you’re still feeding when the nighttime temperatures drop into the 40s, syrup left overnight in the feeder may be too cold by the next morning. Try feeding only what they will take in 24 hours and then give them a new round of fresh warm syrup each morning. You can get the last few quarts taken down this way. (This will quickly get tedious, but next year you’ll be motivated to start feeding earlier!)
Whenever you’re feeding, you are at increased risk of robbing, so reduced entrances and robbing screens are needed to prevent it from getting started. Both front entrance robbing screens and ones designed for nucs (which can also be used over upper entrances) are helpful.