Feeding Honey Bees: What, When, Why?


Author: Heather Broccard-Bell, Ph.D., Honey Bee Health Researcher

Feeding is one of those controversial honey bee topics that might best be avoided in polite company. A lot of different beekeepers have a lot of different (often extremely passionate) opinions. Some of those differences come down to living in different areas of the world. Others are personal preferences and simply what has worked (or at least what hasn’t not worked) in the past.

The goal of this post is not so much to tell you exactly what you should or should not be doing. Rather, it is to give you an appreciation of why you might (or might not) need to feed your honey bees, and to provide you with some general guidelines.

The Honey Bee’s Natural Food Sources

Honey bees naturally collect two main types of food: nectar and pollen [i]. Both are produced by flowering plants, including trees [ii].

  • Nectar is high in sugars and is the main source of carbohydrates for the colony. Honey bees require carbohydrates for energy—for example, to power their flight muscles so they can fly.
  • Pollen is the primary protein source for the colony. Just like in humans, bees need protein to grow bodies. For honey bee colonies, that means brood production.

A colony with insufficient pollen will fail to grow, but a colony with insufficient nectar will die. It is therefore especially important to understand how and when to supplement nectar.

See Figure 1: A honey bee gathering nectar from a flower. Pollen grains can be seen stuck to the hairs on her body. Photo credit: H. Broccard-Bell.

The needs of a colony vary throughout the year and depend on the local climate. In Canada, colonies expand rapidly in the spring, which means they need a lot of pollen to raise brood. During Canadian fall, colonies don’t need so much protein, since they reduce their numbers in preparation for winter. Colony focus in the fall is to store high-energy food to ensure they can keep the inside of the hive warm throughout the winter. Nectar is the name of the game for autumn in Canada.

While honey bees like to keep the temperature inside colonies about 33-36°C (91-97°F), this warm environment is less than ideal for food storage. The high moisture content of nectar means it tends to ferment inside the warm hive. So what do you do if you are an animal that needs nectar, but no fresh nectar is available for several months? Honey bees have solved this storage problem by evolving the capacity to turn nectar into honey. By evaporating off excess moisture and adding enzymes, honey bees increase the shelf-life of nectar exponentially [iii].

As beekeepers, we should never forget: bees don’t make honey for our sake. When beekeepers harvest honey, or when there is a lack of environmental nectar available (a “dearth”), at least some of those calories need to be replaced so the colony does not starve.

Some beekeepers simply leave enough honey on the colonies for the bees to survive the winter at harvest time. This approach works, unless there is a nectar dearth leading to insufficient honey being stored to meet the needs of the colony. It is also important to pay close attention to your local laws regarding feeding bees honey. Due to the risk of spreading American Foulbrood Disease, it is illegal in many areas (including Ontario) to feed honey back to colonies (e.g., to remove frames and then replace them at some later point). Therefore, it is important to know how to feed sugar syrup your bees, should the need arise.

It’s About Timing—but it isn’t Clockwork

Finding the optimal time to feed your colonies is important for their survival and productivity. When to feed depends on your local conditions. A good local beekeeping calendar, such as this one from the Central Beekeepers Association in New Brunswick, Canada will help you understand what your colonies need at different times of the year.

In southern Ontario, Canada, the climate is warm and wet—at least in summer. Plants typically produce a lot of flowers throughout the season, and consequently, abundant pollen and nectar. Supplemental feeding of sugar syrup in Ontario happens in early spring and/or late fall, either before or after the major floral blooms.

Things are very different in southern California, where I spent the past seven years studying bees. Summers and falls are hot and dry, with rainfall typically occurring only during the winter and spring. Summer/fall is therefore the height of the feeding season—at least in southern California [iv]. Still, the date on the calendar isn’t always a good indicator of what is happening out in the real world.

“Bees don’t read books about bees,” is a prudent phrase I’ve heard more than once.

The best advice I can give you is to know how much food your colonies have in reserve, and what their requirements are at that time. Pollen, which comes in a rainbow of colours, is readily visible coming into colonies on the legs of foragers. Nectar is harder to see, since bees carry it in their internal honey stomachs. But to really understand how much food is available to the bees, you will need to open up your colony and have a look.

Stored nectar appears as clear, shiny liquid inside cells. Once the nectar has been transformed into honey, the bees place a layer of wax over it. Capped honey can be distinguished from capped brood by its more translucent appearance. Brood cappings are solid brown, and each cell is individually capped, whereas capped honey has a more sheet-like appearance. Stored pollen, which undergoes a fermentation process to become “bee bread, appears as bright yellow, orange, and red-coloured cells. Stored pollen is often located deeper inside cells and requires good lighting to see.

Even if you don’t crack your colonies, doing a “heft test” should give you a decent idea of what is happening inside your colony, at least in terms of honey. The heft test is performed by lifting or tipping your colony up slightly to check the approximate weight of the brood chamber (checkout this how-to video on the heft test). This is particularly important at the beginning of a nectar dearth. The Ontario Ministry of Agriculture, Food, and Rural Affairs (OMAFRA) says that colonies should weigh at least 32 kg (70 lb) for a single brood chamber, or 45 kg (100 lb) for a double brood chamber prior to winter. A colony that is too light needs to be fed.

Of course, it’s important to understand that there are also times when bees should not be fed—most notably, ahead of honey production. Honey consumers value the additional flavours and nutrients provided by honey made from floral nectar. Sugar syrup honey does not contain these same special elements and is therefore undesirable.

The Right Mix: Feeding Sugar Syrup

Since nectar is what bees need most in the fall in Canada, we need to feed something that will carry out the same function. The best option is to provide a heavy fall syrup, made by mixing water and plain old white table sugar.

For fall feeding in Ontario, OMAFRA recommends feeding each colony 15 L (4 gallons) of supplemental sugar syrup. Syrup should be a 2:1 ratio of sugar in water. In other words, for every 1 L of water you add to your mix, you need 2 L of sugar (or 1 cup water to 2 cups sugar, if you prefer Imperial measurements). While this is a volume to volume ratio, you could just as well use weight measurements to achieve the same ratio (1 kg of water for every 2 kg sugar, for example). And yes, those who remember their high school chemistry will quickly point out that water and sugar have different densities. True, but when it comes to feeding bees, the actual ratio of water to sugar achieved by either method is close enough to 2:1.

A 2:1 sugar to water ratio is quite thick. It will be very difficult to mix the sugar into cold water. The easiest way to get a good mix is to heat everything up in a large pot on your stove. Just make sure to let it cool before handling it!

Once you’ve made your syrup, what do you do with it? There are many different ways to feed sugar syrup to bees. I am not here to recommend any specific one, but I will briefly go through a few of the most common methods.

See Figure 2: Honey bees collecting sugar syrup from an external feeder used in research. Scientists train honey bees to use feeders to answer all kinds of questions about honey bee capabilities and behavior. Karl von Frisch, who won a Nobel Prize for decoding the waggle dance, used similar feeders in his studies. Photo credit: H. Broccard-Bell

Entrance feeders consist of some version of a feeder that fits into the entrance of a colony. One type is constructed of a mason jar with holes punched into the lid. The jar is filled with syrup, and then inverted into a frame that slides into the entrance of the colony. Bees gather the syrup without having to leave the hive, so we call this method “in-hive” feeding.

Hive-top feeders are also popular types of in-hive feeders. They range from pails with holes in the bottom that are set on the top of the inner cover, to specially designed slotted wooden boxes that allow bees to access the syrup without drowning. Some people even fill Ziploc bags with syrup, which are then placed on top of the inner cover, with a small hole cut in the bag.

A final type of popular in-hive feeder is a frame feeder. This device is shaped like a frame, and typically takes the place of 1 or 2 frames within the colony. Frame feeders allow bees to access syrup through small holes in the top.

The other main method of delivering supplemental syrup to colonies is through “open feeding.” This method involves placing feed in large drums or pails outside of the colonies. Open feeding is more straightforward than in-hive feeding, since barrels don’t usually need to be re-filled and you don’t need to open colonies. However, open feeding does suffer from the drawback of being non-targeted. This means you’ll need to be OK with feeding not only your neighbours’ bees, but a host of other sugar-loving creatures as well. While open feeding can be a simpler solution, keep in mind it further exposes your honey bees to other colonies—allowing them to mix and mingle with any potential diseases or pests those colonies may bring to the table.

All Fed Up

I hope that I’ve given you a useful glimpse into the natural lives of honey bees, and that this has in turn helped you to further understand what bees need from us, and when. Happy Fall Feeding!

About Heather Broccard-Bell, Ph.D.

Dr. Heather Broccard-Bell is the Honey Bee Health Researcher at NOD Apiary Products. She is a scientist and educator with over 15 years research and teaching experience. Heather has been focused on investigating issues surrounding honey bee health and communication since 2014. When Heather’s not in the lab, you can usually find her in the bee yard or on a trail hiking with her many pawed pals.

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FOOTNOTES

[i] Food is not all that honey bees collect! Specialized foragers gather water for the colony. A recent study showed that in southern California, swimming pools were major water sources for honey bees [1]! Tree resin and other plant parts are also brought back to the colony to make propolis. Propolis is a sealant and a natural anti-microbial. Honey bees use propolis to keep their colonies clean and dry. Asian honey bees (Apis cerana), closely related to our familiar European Honey Bees (Apis mellifera) were even recently observed collecting animal feces, supposedly to help them combat hornets [2]!

[ii] We talk about nectar and pollen a lot, but why do plants produce these substances? In short: reproduction. Flowering plants have evolved structures to produce sugary nectar as a method of attracting pollinating animals to visit. Once they arrive, pollen grains from other structures in the flower stick to the bodies of the animals. In plants, the cells contained inside pollen grains carry out the same function as sperm in animals. These cells need to fertilize an egg for the cycle of life to continue. But whereas animals can move around, enabling them to carry out reproduction unaided, plants cannot. Thus, pollinators carry the male reproductive cells on their bodies to flowers from other plants, where they can finally meet up with an egg cell (“pollination”). Fortunately for plants and bees, a lot more pollen is produced than is needed to create the next generation of plants. Bees can therefore take advantage of the protein-rich excess to aid their own reproduction, while still being effective pollinators.

[iii] Although it is an often-repeated claim that 3000 year old edible honey has been excavated from tombs in Egypt, I have never yet seen anyone cite the actual study in which this was reported. Regardless, it is a fact that under proper conditions, the shelf-life of honey is effectively decades.

[iv] California is very climactically diverse. Within a few hours’ drive of Los Angeles, you can find desert, chaparral (dry scrubland), inland plains, alpine regions, temperate rain forest, forested lowlands, and densely populated urban areas. It is nearly impossible to capture the climate of California in one statement. 

References

  1. Lau, P. W., & Nieh, J. C. (2016). Salt preferences of honey bee water foragers. Journal of Experimental Biology, 219(6), 790-796.
  2. Mattila, H. R., Otis, G. W., Nguyen, L. T., Pham, H. D., Knight, O. M., & Phan, N. T. (2020). Honey bees (Apis cerana) use animal feces as a tool to defend colonies against group attack by giant hornets (Vespa soror). Plos One, 15(12), e0242668.

 

 

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