Bees and blue: beautiful blue blossoms for happy honey bees

Inside: Here’s a summary of some of the more common bee-attracting plants with blue flowers, blue pollen, or both.

Blue surrounds us from the depths of the oceans to the farthest reaches of the sky. Shades of blue shift and pulsate as clouds meander, sea floors fluctuate, and atmospheric particulates toy with the light. We’ve coined alluring words for these gradations of blue: sapphire, azure, ultramarine, cyan, indigo, and cobalt. And could anything sound more romantic than “cerulean skies”?

Despite the volume of diverse and evolving blues in our daily lives, a sweep of delicate blue flowers shimmering in the sunshine is nothing short of mystical. Why? Perhaps we don’t associate living things with blue, reserving it instead for those boundless expanses of seeming emptiness. Flowers of pink and white and yellow and red seem normal to us while blooms of blue are startling. Unexpected. Freaky.

Mesmerized by blue blooms, many gardeners dedicate entire planting beds to flowers of a particular hue. These folks plant swaths of catmint, bachelor’s buttons, scilla, and borage for their own delight. But no one is as pleased as the bees. Nothing, it seems, is more bee satisfying than a carpet of blue blossoms on a warm spring day. Bees on blue are happy indeed.

The allure of blue pollen

As enchanted as I am by blue flowers, my greatest delight is blue pollen. I’m obsessed with it, chasing blue-legged bees for hours in order to get a single photo. I have lain in the mud for extended mucky stretches, trying to capture a blue-burdened bee on a periwinkle flower against a blueberry sky. I have ordered every blue-pollen-producing plant I can find. Blue on bees is my own happy place.

Blue pollen and blue flowers don’t necessarily go together. Although blue flowers like scilla and baby blue eyes produce satisfying heaps of sapphire pollen, others like chicory and forget-me-nots do not.

Some non-blue flowers produce blue pollen. For example, the opium poppy, Papaver somniferum, is purple, white, or red with bluish-gray pollen, a color similar to those seeds on your poppy-seed bun. For some reason I won’t speculate on, honey bees like to roll in this stuff, emerging from the central disk all quivery and covered in gametes. Another poppy, Papaver orientale, is red with a dark center and dark blue pollen.

Does the color matter?

Blue pollen seems like a gratuitous gesture on the part of mother nature. After all, it is the color of the flowers, the sweetness of the nectar, and the scent oozing from glands that attract bees. The color of the pollen shouldn’t much matter. And, as we all know, bees will collect it regardless of the color — white, green, yellow, pink, brown, and gray all work for them. So why did nature go to all that trouble? I haven’t a clue, but I’m transfixed.

My first encounter with blue pollen was not in a pollen basket or on a stigma. Instead, it was in a frame of pollen. The entire frame was heavy with pollen in shades of lemon, egg yolk, tangerine, and lime. But scattered among the familiar colors were hexagons of bright, ethereal blue. I was mesmerized. What was producing such an unexpected color? I’ve been on the hunt ever since.

A true blue native is a rare find

As with many extraordinary things, neither blue flowers nor blue pollen is common. When I page through local field guides filled with alluring photos of native plants, I see very few that are “really most sincerely” blue. Some are close, but oftentimes they lean toward purple or magenta.

Northern bluebells (Mertensia paniculata) are blue except when they are pink. Oyster leaf (Mertensia maritima), a type of bluebell, also has blue flowers except when they are white. Introduced creeping charlie or ground ivy (Glecoma hederacea) is described as having blue or blue-purple flowers but they look pink to me.

Among the bluest is American brooklime (Veronica beccabunga). It’s a small flower that grows in wet ground and shallow marshes, always attended by tiny black bees of some sort. It’s similar to alpine speedwell (Veronica wormskjoldii) another blue-flowered, moisture-loving plant. Then we have blue-eyed mary (Collinsia parviflora), blue penstemon (Penstemon serrulatus), and introduced chicory (Cichorium intybus).

The bluest wildflower I’ve seen here in the Pacific Northwest is common camas (Camassia quamash). In early spring, fields dense with camas lilies look like lakes when viewed from a distance. This optical illusion startled me more than once and is amazing to behold.

Blue native flowers with blue pollen

Baby blue eyes, Nemophilia menziesii, is a California native that the USDA-ARS selected as excellent bee forage. In the same genus as five spot, it is often planted in bee pastures designed for native bee species. It blooms early, re-seeds easily, and will grow in most areas of the United States. The flower and the pollen are fragile blue and attract honey bees as well as wild pollinators.

Two other blue wildflowers with blue pollen are wild geranium and bird’s-eye gilia (Gilia tricolor). Wild geranium, also known as cranesbill, comes in various colors from blue to purplish pink. Several of the species have distinctly blue pollen.

Bird’s-eye gilia is a lovely, small tricolored annual that grows low to the ground. The flowers range in color from pale blue to near violet and the stamens produce clouds of tepid baby-blue pollen. These flowers attract more bees when you plant lots of them because they’re so tiny. But because they are loaded with both pollen and nectar, they draw the smaller native bees in great numbers. Some visitors are so small, you might not recognize them as bees, but you will definitely recognize the hummingbirds and butterflies in the mix.

Colors can be unpredictable

Oftentimes the descriptions in books seem at odds with the photos. I suppose the author, the light, the printing process, or some other variable affects the outcome, but I’d be hard-pressed to describe some of the images as any sort of blue.

The same goes for pollen. Up close, many pollens called blue seem more or less gray. However, here in the Pacific Northwest, we have one kind of wild pollen that is blue beyond a shadow of a doubt, cobalt perhaps, and that’s fireweed. The flower itself is dark pink, the honey is water-white, but the pollen is blue beyond measure — a shade to match no other.

Shedding a different light

Even though we and the bees like blue flowers, we see differently. Because a bee’s eyes sense shorter wavelengths than human eyes do, the bee sees a different range of colors. She can see ultraviolet, something we cannot do. But at the other end of the visible spectrum, we can see the long wavelengths of red, something she cannot do.

Humans detect light waves from about 380 to about 750 nanometers, but bees and many other insects see shorter wavelengths from roughly 300 to 650 nanometers. That slight shift is what gives bees the gift of ultraviolet but steals away the reds. But does that explain why bees seem to love flowers in the purple/violet/blue range? Not really.

What’s the real reason bees love blue?

Several sources I read said that bees love blue flowers because they secrete more nectar than other colors. But that sounds like chicken-or-the-egg reasoning. Isn’t it possible that blue flowers secrete lots of nectar because bees like to visit them, and it makes good survival sense to keep those visitors interested for generations to come? In any case, I can find no documents supporting the claim of more nectar.

Other sources say that the entire purple/violet/blue range gives off an ultraviolet glow that naturally attracts bees. But again I wonder which came first, the bees’ preference for the glow or the glow itself. Since flowering plants and bees evolved together over millennia, those traits probably arose together, baby steps at a time. What we see now is one point on an ongoing evolutionary trajectory. At least, that’s my guess.

A trick of the light

When we leave the world of native plants and walk the aisles of our favorite nursery, we see many more blue-flavored flowers than we see in nature. Apparently, blue in the petals is associated with anthocyanins, but an assortment of other factors come into play before they actually look blue. Some breeders say there is no such thing as true blue in the plant kingdom and that seemingly blue flowers are merely tricks of the light.

But aren’t all colors simply tricks of the light? Aren’t colors merely perceptions passed along a trail of neurons in our eyes and brains? I don’t want to drown in semantics here, so I’m just going to call them blue flowers and not worry about the chemical composition or how and why our brains label them blue.

Breeding for blue

Like me and the bees, plant breeders have long obsessed over blue flowers, spending lifetimes in search of blue tulips and daffodils, blue roses and crocuses. As a result, quite a few dazzling blue species line the shelves, beckoning us from seed packets and peat pots.

When we are planting for pollinators, the trick is to find those rare cultivars that solicit us as well as the bees. Attracting humans is easy, a simple matter of looking good. But for the bees they must be more than pretty, providing plentiful nectar, nutritious pollen, or both.

Other issues arise as well. What some people consider invasive, others consider impossible to grow. What some think is beautiful, others consider an eyesore. And what some consider a lovely fragrance makes others want to retch.

Cultivated blue blooms for bees

Without any guarantees of invasiveness, beauty, or fragrance, I’ve listed a few of my favorite blue-flowered blooms that bees seem to love. Colors shift from crop to crop, so what looks blue to me might look purple to you, and what grows in my garden might not succeed in yours. But you know that already. Just remember these suggestions are not for you, they’re for the bees.

Early-spring blues

One of my favorite spring flowers is Siberian squill (Scilla siberica). Depending on where you live, it may be invasive, so check before planting. Where I live, I can’t keep it alive from one year to the next, no matter how many hundreds I plant. I love this species because it appears super early with soft blue blooms and scads of denim pollen. It attracts multiple species of early bees, including honey bees, Andrena mining bees, and mason bees.

Forget-me-not (Myosotis sylvatica) is an alluring spring plant with sky-blue flowers. I wish I had the patience to grow them more frequently, but it’s a biennial and two years seems like a long time to wait. But the flowers are lovely. Since I began growing them beneath my mason bee houses, I’ve frequently noticed the masons mating among them. I get that.

For years, I’ve grown vinca (Vinca minor) as a shade-tolerant groundcover. Mine have blue flowers, but some varieties are more purple than blue. I love this plant because it’s easy to grow, requires little attention, and produces abundant blue blooms for many weeks in spring. It’s also called periwinkle, which describes the flower color to a tee. I don’t recall ever seeing a honey bee on the flowers, but they are well-attended by mason bees, Andrena mining bees, and assorted bumble bees.

Summer blues

One plant that always reminds me of honey bees is borage (Borago officinalis). In my book, borage is an ugly name for a stunning plant. It’s one of the few flowers I’m willing to lie on the ground to photograph because the flower shape almost compels it, nodding forward and down away from the sun. There is almost no bee that doesn’t look great sitting on a borage flower, almost like a studio photographer designed it that way. And the flowers are truly blue (so much for tricks of the light). As for the pollen, steel blue is the shade that comes to mind — blue with a bit of gray mixed in.

Batchelor’s buttons (Centaurea cyanus) is another summer blue, but very different from borage. Batchelor’s buttons are dark blue flowers that are extremely attractive to honey bees. I find the flowers hard to photograph though because they seem to swallow the light, disappearing it into the recesses between the petals. Luckily, the bees don’t seem to notice but keep right on foraging.

Viper’s bugloss (Echium vulgare) in the same family as borage, sports vibrant blue flowers with contrasting red filaments, and anthers that produce brilliant blue pollen. It will grow in dry and barren wasteland and seems to prefer poor soil and inattention. It also produces copious amounts of nectar that honey bees love. Viper’s bugloss would be the beekeeper’s dream come true if it weren’t invasive in some areas.

Late season blues

Later in the season we see Russian sage (Perovskia atriplicifolia) and one of my favorite plants, blue anise sage (Salvia guaranitica). These are stellar bee plants because they produce lots of nectar in a season when little else is in bloom. Russian sage (not from Russia and not a sage) is a small woody shrub with smokey-blue flowers. It is low-maintenance, drought-tolerant, and not eaten by deer or rabbits. At the same time, it is popular with many pollinators, including bees, butterflies, and hover flies.

My favorite salvia is S. guaranitica. I especially like a tall cultivar called “Black and Blue” which has striking flowers of navy blue and deep purple that almost appear black. These flowers are long and deep, but they attract hummingbirds, butterflies, and some bees. The bees that manage to get the nectar, including honey bees, are mostly nectar robbers, drilling through the base of the calyx to get to the pool of sweet goodness.

January is for seed catalogs

You can find many more blue-flowered plants that your pollinators (and you) will love. Because we can expect many more cold winter evenings before spring, you can spend a few of those curled up with your favorite seed catalogs, dreaming of warmer days ahead. Take notes and plan to give your pollinators a treat in 2023, one that is all wrapped up in blue.

Rusty
Honey Bee Suite

Addendum

Since I posted this article, several people have written to say I missed their favorite blue flower/blue pollen plant. Caryopteris is a small shrub in the mint family (Lamiaceae) that blooms in late summer into early fall. An import from East Asia, the plant is a bee and butterfly magnet with rich nectar and dark blue pollen.

Kat from Ellensburg, WA says, “Besides honey bees, caryopteris attracts tons of other insects as well—I’d say it’s similar to a currant in the diversity you’ll find on it, with a longer (and different) bloom time than the currants have. One other note is that the foliage is highly scented. I love to rub the leaves between my hands and find it a real mood-lifter.”

There are several cultivars and crosses, but one called Bluebeard (Caryopteris x clandonensis) is readily available and beloved by gardeners. In the photo below, you can see the dark blue pollen on the anthers.

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