pollination

Bees and flowers: best friends forever

It wasn’t long ago that nearly all beekeepers came into the practice from some agrarian pursuit. These people were gardeners, farmers, orchardists, or dairymen who recognized the benefit of keeping honey bees. Others got into it because beekeeping was part of a treasured childhood. How often do you hear, “My father kept bees” or “My grandfather kept bees.” In many rural towns, hives were as common as barns and silos — just a normal part of the landscape.

This article first appeared in American Bee Journal, Volume 161 No. 9, September 2021, pp. 967-970.

Besides their love of bees, these folks had something else in common — a working knowledge of plant life. They understood the annual cycles of growth, bloom, seed set, and die-back, and they recognized factors that influenced plant health and productivity. They even predicted good years and bad, fretting over rainfall, drought, and windstorms, and they knew how to read phenological signs.

Many of us grew up with folk phenology handed down by the same people who instilled our love of bees. “Plant potatoes when the dandelions bloom,” is an adage I still use. You can “prune your roses when the crocus bloom.” And, of course, you can predict a good harvest if your corn is “knee high by the Fourth of July.”

Our forebears read weather signs, too. “Red in the morning, sailors take warning,” was a reliable predictor of foul weather, as opposed to “Red at night, sailor’s delight,” which meant tomorrow would be gorgeous. Try it. It works because moisture levels and dust concentrations in the atmosphere affect the colors we see, and because our weather system moves from west to east, when and where we see the red makes a difference.

Because folk knowledge was common knowledge, rural beekeepers grew up knowing the basics of plant science. Perhaps they didn’t call it botany or plant physiology, but they had an instinctive feel for how natural systems worked.

Where have all the basics gone?

Today, I hear confusion about plants in the questions people ask. For instance, a new Pacific Northwest beekeeper said, “I learned the big honey crop is blackberries. We have lots, so I added my supers just as the berries began to ripen, but I got nothing. What happened?”

And another, “I don’t understand how the bees make honey from pollen. Do they use the syrup to make it liquid?”

I can empathize with their frustration. Many of these new beekeepers simply do not understand the intersection between plants and their pollinators. Trying to learn beekeeping without a grounding in plant science is daunting because the two disciplines cannot be separated. It’s like trying to make a peanut butter and jelly sandwich without the jelly — it just doesn’t work.

Like a honey bee, this green Agapostemon enjoys a wide range of flower types and colors. All photos by Rusty Burlew.
Like a honey bee, this green Agapostemon enjoys a wide range of flower types and colors. All photos by Rusty Burlew.

Two sides of the same coin

Despite what the books don’t say, the craft of beekeeping has two fundamental dependencies: honey bees and flowers. You simply cannot keep bees without flowers, yet we’ve left plants out of the basic instruction manuals altogether or mention them only as an afterthought.

Back in the day when beekeepers came from agrarian backgrounds, you could probably get away with this. A beekeeping primer didn’t need to detail how flowers work because those farmers and dairymen had a feel for the whole botanical reproduction thing. But with many of our new beekeepers emerging from a Facebook-dominated culture, you simply must explain the details. Every last one.

Ignoring flowers is not an option

To better understand what we currently teach newbies about the connection between bees and flowers, I began leafing through my stash of beginner books. The books tell you what to buy, where to put your hives, and how to install your bees. They explain the basic difference between workers, drones, and queens, and (ever so briefly) mention seasonal fluctuations in population. Some explain how to light a smoker, catch a swarm, and treat varroa, while others offer tips on honey harvest and fall management. Jumping the gun, some detail the processes of marketing honey and making soap.

But nowhere do these books explain the complex codependency between bees and flowers. They don’t mention the parts of a flower, such as stamens, anthers, and nectaries. They don’t explain that bees need both nectar and pollen, or that flowers can be males with no nectar or females with no pollen. One of the best-selling beginner books of all time has less than a half-page devoted to flowering plants.

 This Anthophora, a common digger bee, is happy with anthers that are well above the petals. Most bees don’t collect a lot of nectar, so pollen is the most important thing.
This Anthophora, a common digger bee, is happy with anthers that are well above the petals. Most bees don’t collect a lot of nectar, so pollen is the most important thing.

The birds and the bees

For several years, I worked as a volunteer in the Washington State prison system. I taught plant propagation, soil fertility, and greenhouse management to the guests before the superintendent transferred me “outside the fence.” Memorable moments arose from both sides of the razor wire, but I will never forget one afternoon in the greenhouse when I was teaching a dozen well-tattooed tough guys in their 20s, 30s, and 40s about plant sex. I brought some daffodils to pull apart while I described the function of the stamens, anthers, ovaries, and the role insects play in fertilization and seed formation.

Those guys flatly and defiantly refused to believe a word of it. First came flushed faces, uneasy shuffling, and silent gazes at the concrete floor and the orderly rows of plastic pots. Finally, the bravest among them said, “Aw, cut it out. We ain’t stupid. Plants don’t got like sperm and stuff.”

This produced guffaws, giggles, and knowing glances. They all instantly agreed I was trying to pull a fast one. “Fantastic story!” declared one. “Now tell us the truth.” Then they all roared with raucous laughter, creating enough commotion to bring guards with guns storming into the greenhouse.

This took a heap of creativity to overcome. Some of the men eventually came around and accepted the idea of plant sex, however passive it might be. Others, not so much. Within a few weeks, the superintendent asked me to help design a beekeeping program, and after that, he assigned the greenhouse to someone else. Was that a demotion? I never found out, but I was happy to be outside with the bees.

Science takes a back seat

The prison population may be atypical, but it’s not far from the norm. Here in the states, basic science education is at the bottom of our priority list, leaving large swaths of the populace clueless about how the natural world works. For our purposes, that means we must teach new beekeepers the basic biology of how bees and flowering plants interact.

We mislead newbies with our word choices. When we speak of the blackberry flow, I’m sure many beginners think the nectar comes from the berries themselves. We know what we’re talking about but they don’t, even though they think they do. It’s a semantics nightmare.

Similarly, many beekeepers attribute blue honey to blueberries or elderberries, but blueberry honey is amber, not blue, and elderberries don’t secrete nectar at all. Oh sure, we’ve all seen honey bees sipping on a ripe berry, but that’s not the normal course of things. Since the details are often confusing, we must take the time to explain.

 This Colletes, a cellophane bee, is going to the base of the flower where the nectaries are usually found. Males and hungry females will ignore the pollen while searching for a snack.
This Colletes, a cellophane bee, is going to the base of the flower where the nectaries are usually found. Males and hungry females will ignore the pollen while searching for a snack.

The parts of a flower

Beekeepers need to know that nectar comes from nectaries and pollen comes from anthers. In addition, they need to know that a flower may produce nectar, pollen, both, or neither. So no, not all flowers are created equal. We must dispel the notion that a few random flowers scattered about will support a colony. Maybe those particular flowers are beneficial to bees, but maybe not. A beekeeper simply must know more about them.

After basic plant morphology, I would explain the coevolution of bees and flowering plants. It’s a topic that’s relevant to many contemporary discussions, including the one about competition among bees.

A currency of pollen

So what would I tell a new beekeeper about plants? Well, I’d start with structure:

  • Flowers are a vital part of sexual reproduction in plants.
  • Depending on the species, a plant can have male flowers or female flowers, or what we call perfect flowers — ones with both male and female parts.
  • The female part — the pistil — has a stigma, style, and ovary. The stigma is the receptive part, the style is a tube, and the ovary holds the ovules that become seeds after fertilization.
  • The male part — the stamen — has an anther, which produces pollen, and a filament, which acts like a flagpole to hold the anther aloft.
  • Pollen from the proper species needs to land on the stigma, travel down the style, and fertilize the ovary. Nothing to it.

The problem with this simple system is that plants cannot run around looking for mates. They can’t hop, jog, fly, or swim. All they can do is sit there, rooted to the ground, and wait.

Long ago and far away, while wilting of boredom, an enterprising plant thought of flagging down a passing insect and asking for help. The deal went something like this: “I will pay you X if you agree to do Y.”

That may sound elementary, but it worked, and pollination today is no different. The plant pays X in nectar or pollen in return for Y, which is the door-to-door delivery of pollen from a similar plant.

Of course, the plant needed an ad campaign to find a workforce. The marketing department developed an extensive plan to target the insects, and all of it was expensive. Brightly colored petals, alluring smells, enticing beverages, soothing oils, and delicious hors d’oeuvres — even fluorescent welcome mats. Like a five-star restaurant, all the senses of the target audience were considered.

For their part, the bees were enchanted with all this attention and decided to take advantage of the offer by wearing special pollen-attractive clothing while carrying sacks and saddlebags to transport the goods. They even weaned their young ‘uns from meat and began feeding them pollen, a move that was safer in the long run, considering pollen doesn’t resist capture.

This honey bee is collecting pollen from Siberian squill. Honey bees usually collect either nectar or pollen on any given trip, but sometimes an individual will collect both at the same time.
This honey bee is collecting pollen from Siberian squill. Honey bees usually collect either nectar or pollen on any given trip, but sometimes an individual will collect both at the same time.

Bees and flowers are built for the common good

Throughout millennia, while the flowers tried desperately to attract more bees, the bees developed systems to harvest and transport the goods ever more efficiently. We call this co-evolution. Today, bees and their favorite flowers fit together like a lock and key. They have special intimate relationships that we mortals might miss if we’re not paying attention.

One good example is tongue length. You will see references to long-tongued bees and short-tongued bees, but in reality, we find a continuum of tongue lengths from stubby to spectacular. We consider honey bees a long-tongued species but they fall on the short end of the long-tongue spectrum.

Orchid bees have tongues that can reach the bottom of an orchid blossom, which means their tongues are longer than their bodies. Even tiny bees may have relatively long tongues, although the absolute length of their tongue is short. Not surprisingly, they prefer itsy-bitsy flowers that we may describe as flat or shallow.

Other flower features may attract or repel certain bees. Some bees, including honey bees, revile excessively large pollen grains such as those produced by hibiscus (although they like the nectar). Yet those humongous sticky treats are adored by others such as the hibiscus turret bee, Ptilothrix bombiformis.

Sugar concentration makes a difference, too. Honey bees like super-sweet nectar, which makes sense when you consider they dehydrate it into honey. Bees that don’t store nectar but simply want an occasional energy drink are happy with a more watery refreshment.

Competition for flowers

So do honey bees compete with native bees? Of course. All living things compete for scarce resources, but it’s something that’s nearly impossible to quantify. As a beekeeper begins to understand the interplay between bees and their favorite plants, the complexity of the question becomes obvious.

One of the trickiest variables is flower shape. As a result of coevolution, bees seek certain flowers and avoid others. Some bees fit into their favorite blooms the way Dorothy fit into the ruby slippers — a match made in Oz. Watch a bumble bee disappear into a foxglove and you get the idea. They were simply made for each other.

Not only must the fit be right, but the tools each bee carries must match the job. So do honey bees compete with bumble bees on tomato plants? Never, since honey bees cannot sonicate. Do honey bees compete with mining bees on apple trees? Sometimes. Is it a problem? It depends. Many orchard pollinators fly at colder temperatures than honey bees, giving them a daily head start.

The amount of competition among bees varies with available forage, season, and the number and type of plants in bloom at any point in time. In addition, competition levels will vary with the specific location, the particular sample, and the current weather.

This honey bee is standing on the central disk of a dahlia, collecting pollen, but dahlias provide both pollen and nectar.
This honey bee is standing on the central disk of a dahlia, collecting pollen, but dahlias provide both pollen and nectar.

Those nasty stamens

Bees also learn how to handle flowers that are less than ideal. Did you ever wonder why alfalfa seed growers are not enamored with honey bees? Since honey bees can make barrels of tasty alfalfa honey, you might think they were pollinating like crazy. But no. In fact, in some places, like the Touchet Valley of Washington State, beekeepers are not allowed to bring honey bees into the county during the alfalfa growing season.

The reason for the ban is flower shape. Alfalfa stamens are held under tension within the flower. When a bee reaches for the nectar, the stamens and the pistil are tripped, an action that bops the pollinator squarely on the head. This deposits pollen all over her body, much to the flower’s advantage. But honey bees don’t like the sensation of being constantly clobbered by unruly stamens, so they soon learn to rob the nectar by drilling a hole beneath the flower where they are safe. Nectar robbing can yield a great crop of honey, but it doesn’t pollinate anything.

Instead of honey bees, many growers use alfalfa leafcutting bees and alkali bees that don’t seem bothered by violent violet-hued flowers. But the presence of too many nectar-robbing honey bees in the field can lower the rate of pollination. If the honey bees drain all the nectar, the bees doing all the work may encounter a food shortage during pollen-collecting times.

On the other hand, some California alfalfa growers use only honey bees for pollination. The trick is to use “naïve” honey bees, ones that haven’t yet learned the art of nectar robbing. To do this, growers use many colonies per acre in order to assure a continuous supply of young and naïve bees to pollinate the entire crop, a technique called pollination saturation.

Watching and learning

I love to watch the bees slot themselves into their preferred flowers or see them spiral upward around a statuesque lamb’s ear, checking each blossom along the way. I adore the whining squeal of buzz pollination as it vibrates the pollen from a bloom. I’m charmed by a tiny Halictus as it winds itself around the center of a buttercup, or a leafcutter carving perfect disks so she can wrap her young in a quilt of petals.

It’s fun to speculate why a bee chooses a particular flower. Is it the size, shape, or color? Is it fragrant odors or extra-sweet nectar? Attractive resin? Or maybe it simply seems non-threatening or more convenient. Some bees have eclectic tastes, giving them many options. Other bees specialize in a particular family of plants, which limits their choices, but no bees like all flowers. It’s never one-size-fits-all.

The play between flower and bee is nature at its finest, so don’t stop watching your bees at the hive entrance but follow them to the corner market. Watch them select the consummate flower, the one that will work for whatever they have in mind. The bee/plant relationship is a complex and fascinating subject, one of the most curious things life as a beekeeper can show us.

Rusty
Honey Bee Suite

The Melissodes are a type of longhorn bee, meaning the males have extremely long antennae. Like most Melissodes, this blue-eyed female is attracted to composite flowers, in this case, tansy ragwort.
The Melissodes are a type of longhorn bee, meaning the males have extremely long antennae. Like most Melissodes, this blue-eyed female is attracted to composite flowers, in this case, tansy ragwort.

18 Comments

  • I am always amazed at your prose but even more so with the artistry of your photographs. Had a fun day last week with a couple of days of full flight for the hives and their readily observed pollen rapture over our native filberts.

  • Wow! I consider myself scientifically knowledgeable, but you always seem to throw out new information for me to take in. Just the information about alfalfa was fascinating. Thank you for sharing it all. Anything that increases my appreciation of the natural world is worth reading…twice, in your case.

  • Wow, this was so good. Educational and entertaining and so many things. So nice to see the honeybeesuite emails arriving again.

    Lambs ear, good for honey bees? Do they like it? I’ve got tons of it, mostly the white variety whereas my neighbor seems to have more of a blue/violet.

  • Hi Rusty
    I guess I came to beekeeping the opposite way. When I was growing up my main interests were surfing, electric guitar, and girls. My father wanted me to be a doctor, or at least go to college. I turned my back on all of it in 1974 to become a professional beekeeper. I suppose beekeeping is the polar opposite of everything I had known as a kid growing up in the suburbs. I still have the guitar I bought in 1966, though.
    Pete B

  • Excellent blog!! Yes, it’s all about the flowers. I’m currently in San Diego doing my CA Master project which is collecting pollen and it will be analyzed for amino acid, protein, and sterol contents and compared. I’m just reading about the “sexes” of all the plants in my area from various books, so fascinating. Like you, I have been observing and documenting/taking pictures of all my neighborhood sources the bees are foraging on and what exactly they are taking back to their colony. I love your blogs and have learned so much from you. You are always my first “go-to” when I have specific questions. Thanks so much:)

  • Excellent article Rusty. I was a gardener first before I became a beekeeper. I am now learning which plants benefit my bees so am constantly ordering new seeds and plants for the wild bee garden. This one I do not cultivate as most of the plants are native and spread. So it is being let go to spread where it wants to next to my bees.

  • You have a talent for writing lucid ideas that strike an emotional cord. Bravo. My “Bee” journey has been long and winding. My mother’s father kept bees over a hundred years ago. I remember their farm in the Ozarks. They kept bees, pigeons, milk cows, pigs and anything that could help them survive, including a 2-acre garden. Seven people survived on 80 acres of rocky ground. No electricity. No running water. I love “our” bees. We actually gave up because I had been so clumsy with them. A swarm moved into a vacant hive last year, fully two months before our typical swarm time. My only comment is that everything wants to live. Thank you so much for this blog, you are a blessing.

  • I really enjoyed this article, I had no idea I knew so little about pollination, especially alfalfa.
    Also, I’m thinking about planting a quarter acre of buckwheat for my four hives. I heard too much of one type of flower is bad for bees. Do you think a quarter acre of buckwheat would negatively affect them? I wouldn’t want to plant anything that could harm them. Ideally I’d plant something that could help them.

  • I wish all want-to-be beekeepers could read this post. You really did an excellent job describing the need for flowers for bees. As an ex-honeybee keeper and life long gardener, I get upset when so many honeybees find my garden now that I understand that if honey bees are extracting the flower resources, there is less for the native bees which I try to support. Years ago, I was appalled when I visited the property of a serious beekeeper and saw no garden, no flowering plants at all. Their bees became in my mind like robbers of all their neighbors. It seems if there is enough room for a beehive on a property, there should be enough for some sort of garden. I wonder if we will ever get to the point where beekeeping is only recommended if there are enough gardens in the area for all these important insects. I hope not since beekeeping is such a fun and interesting hobby that can introduce all family members to so many aspects of the natural world. But on the other hand, I would limit the number of hives so there is more of a chance for the native bees to get what they need.

  • I love this blog! I observed and read somewhere, that flowers don’t produce nectar during certain times of the day, and hence no bees on our honeysuckle in the afternoon, but buzzing in the morning. On the other hand, our Mexican Sage is fully occupied the entire day. Will start recording the observations and see if there is indeed a pattern.

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