Flowers Sweeten Up When They Sense Bees Buzzing

A new study suggests plants can 'hear' the humming of nearby pollinators and increase their sugar content in response

It's a common assumption that auditory information is reserved for living things with ears and that creatures without cochlea—namely plants—don't tune into a bee buzzing or the wind whistling. But a new study suggests the plants are listening, and some flowers even sweeten up their nectar when they sense a pollinator approaching.

Sound is ubiquitous; plenty of species have harnessed the power of sound to their evolutionary advantage in some way or another—a wolf howls and rabbits run; a deer hears a thunder strike in the distance and seeks shelter, and birds sing to attract their mates. Plants have withstood the test of time, so logically so, they must react to such a crucial sensory tool as well, right? This question is the essentially the basis of Tel Aviv University evolutionary theoretician Lilach Hadany's interest in pursuing the new study, reports Michelle Z. Donahue at National Geographic.

Since sound is propagated as a wave, it doesn't always take the complex set of ear bones and hair cells found in mammal ears to detect the presence of sound, just the ability to perceive vibrations.

To test the idea, Hadany and her team looked at the relationship between bees and flowers. The team exposed the beach evening primrose, Oenothera drummondii, to five types of sound: silence, the buzz of a bee from four inches away, and low, intermediate and high pitched sounds produced by a computer, Donahue writes. They then measured the amount of nectar that the flowers produced after being exposed to the sound.

Blossoms exposed to silence as well as high-frequency and intermediate-frequency waves produced the baseline amount of sugar expected in their nectar. However, the blooms exposed to the bee's buzz and low-frequency sounds bumped their sugar content up 12 to 20 percent within three minutes of being exposed to the hum. In other words, when they "heard" a bee approaching, they sweetened their nectar.

Perhaps this isn't too surprising because—although flowers come in all shapes and sizes—so many are actually rather ear-shaped, with petals forming conical or cupped shapes.

To make sure the sound is what was triggering the flowers to produce sugar, and not some other factor, they placed the blossoms in a laser vibrometer, which records very small movements, and replayed the sounds. They found that the bowl-shaped primroses resonated with the bee sounds and the low-frequency sounds, but did not vibrate with the other frequencies. If flower petals were removed, their sense of "hearing" was disabled as well.

"We were quite surprised when we found out that it actually worked," Hadany tells Donahue. "But after repeating it in other situations, in different seasons, and with plants grown both indoors and outdoors, we feel very confident in the result."

The study appears on the preprint service bioRxiv and has not yet been published in a peer-reviewed journal. But Ed Yong at The Atlantic asked several prominent researchers about the quality of the paper and they were impressed by the study. The science of plant communication is rife with pseudoscience and outlandish claims that have never been proven, meaning any claims need to undergo extra scrutiny. Entomologist Richard Karban from the University of California at Davis, who researches interactions between plants and insect pests, tells Yong that the new study is legitimate, and builds on other recent research showing plants can respond to vibrations.

"The results are amazing," he says. "They're the most convincing data on this subject to date. They're important in forcing the scientific community to confront its skepticism."

Hadany calls the science of plant interaction with sound "phytoacoustics" and says there's still a lot left to learn about how plants perceive sound and the mechanism of those relationships.

"We have to take into account that flowers have evolved with pollinators for a very long time," Hadany tells Donahue. "They are living entities, and they, too, need to survive in the world. It's important for them to be able to sense their environment—especially if they cannot go anywhere."

New industry, opportunity for local entrepreneurs SLOW FLOWERS

Eighty percent of the cut flowers that make up the bouquets of American florists arrive daily from another country. These blooms come from the Middle East, South America and Asia.

This astonishing situation got the attention of Debra Prinzing, a Washington State master gardener volunteer.

Prinzing has a degree in textiles and design and an extensive career in journalism. The author of 10 books, she is a contributor to Better Homes and Gardens and her articles on gardening, architecture and design appear frequently in the Los Angeles Times.

Through the process of researching and writing about the world of seasonal flowers, she wrote a book titled "The 50 Mile Bouquet," published in 2012.

Between the book's covers, she explained in detail that domestically raised flowers could make up a daily flower arrangement 52 weeks of the year.

The book received many excellent reviews and, of course, some critics who argued it was not possible to produce a weekly, year-round fresh homegrown bouquet from local flowers.

Prinzing, a little hot under the collar, went back to the drawing board and produced a second book titled "Slow Flowers: Four Seasons of Locally Grown Bouquets from the Garden, Meadow, and Farm" in 2013.

While the book focuses on flowers, it has many similarities to the "Slow Food Movement" that emphasizes using seasonal and locally produced foods.

Suddenly, Prinzing has become the leader of a popular trend called the "Slow Flower Movement," which earned her the American Horticultural Society's prestigious Frances Jones Poetker Award.

The movement has a website – www.slowflowers.com – that lists growers and florists across the country who are participating in the changing footprint of the American floral industry.

Prinzing, who says, "growing and harvesting flowers is in my DNA," launched her movement four years ago and already has more than 700 businesses across the United States and Canada that have championed her philosophy.

She is the president of Garden Writers Association and a member of the Association of Specialty Cut Flower Growers.

This "Slow Flower Movement" is an opportunity for growth here in the Mahoning Valley.

If you are an entrepreneur or know an entrepreneur who likes to get their hands in the soil, consider the opportunity. There are many university extension resources available regarding the cut-flower business.

My View: Stitches in time preserve Grandma's flowers

Our grandmother, Marian Etta Edgett Smith, loved flowers. She grew roses and begonias, forsythias and foxgloves, sweet peas and tiger lilies. She also loved crafts. She knitted sweaters, crocheted tablecloths and bedspreads, caned chairs and created beautiful hand-sewn quilts.

The quilts were some of her most skilled handiwork and it's no wonder that she had begun working on one with the appropriately named pattern "Grandmother's Flower Garden." It was the most popular quilt design after 1925. Each "flower" consisted of 37 small hexagons: one central hexagon and three outer rows consisting of six, 12 and 18 hexagons, respectively.

In our grandmother's version, the center and the second row consisted of bold solid color fabrics and the outer row was solid white. However, she used fabrics with colorful floral designs for the third row.

Many of the floral-patterned pieces were cut from what had once been 25-pound flour sacks that were sold in the 1930s. These sacks, when emptied, were often saved and used to make diapers, dresses and dish cloths as well as aprons and quilts. In those days, nothing was wasted.

The flowers were entirely hand-sewn and if you were to closely inspect Grandma's handiwork from the back, you would see the beauty of thousands of tiny, perfect stitches. Each stitch was equal in length, and there was equal spacing between stitches, all done with precision eyeballing. When finished, each flower looked similar to a honeycomb, and represented a great deal of skilled labor, and a whole lot of love that Grandma employed while sewing the small pieces together.

But, alas, this quilt was never finished. Grandma grew old and was diagnosed with Alzheimer's disease. She passed away in 1991. While going through her belongings shortly after the funeral, her daughter (and our mother), Marilyn, took those perfectly hand-stitched flowers and lovingly put them in a safe place thinking she might finish the quilt, for she had been taught well the sewing skills of her mother. As we all know, time has a way of slipping through our fingers, like thread through a needle, and the quilt remained unfinished.

Now, our mother is 84 years old and has some physical limitations that make sewing nearly impossible. Still, she never stopped thinking about "Grandma's flowers." Her mind kept needling her, but she required the nimble fingers of someone more able, and thus entered my younger sister, Gerri, who was equally qualified for the task.

After many years since Grandma's passing, our mother decided that instead of constructing one quilt, it would be more meaningful for those who fondly remembered Grandma Marian to each have one of those lovingly made flowers.

Most recently, the process began for my sister. She painstakingly ironed each raw edge under, often while having a one-sided, teary-eyed "conversation" with Grandma, thanking her for passing along the love of crafting to her children, grandchildren and even great-grandchildren. She searched for the perfect complimentary background color for each flower, cut a rectangular piece, hemmed the edges and sewed a single flower to the center.

Repeating the process many times allowed the creation of numerous finished pieces (a deconstructed quilt, if you will), each to be used as a wall hanging or framed under glass.

Now, 27 years after her death, and who knows how many years since the quilt pieces were first started, Grandma's flowers are being delivered to those who lovingly remember Marian Etta Edgett Smith. There's no better way to keep Grandma and her love of flowers and crafts alive.

Enjoy flowers' beauty, wild or otherwise

We have all experienced or seen pictures of beautiful fields of flowers. The colors are amazing, and I can only imagine the pride the grower must feel.

I think my favorite flower is the bluebonnet. Texas is famous for them. When thinking of these beautiful flowers I am reminded that not all are intentionally grown, such as those the farmer plants. Some flowers are wildflowers; they spring up where they will and are nurtured and cared for by only a loving God.

The intentional and wildflowers grow under different circumstances. Both are beautiful in their own special way. When they are gathered together and arranged by a special touch, the outcome is a thing of beauty.

Autumn and winter are times when we typically think of the holidays, family and friends. It can be a time when many families come together. This can be a time of celebration for the "intentional" and a time of difficulty for the "wildflowers."

You see, the intentional usually have had someone taking care of them from the beginning — planting, watering, fertilizing — in the best possible conditions. The wildflowers, however, had to go it alone with only the Lord’s care.

Do your family and circle of friends have intentionals and wildflowers? We may have all come through different circumstances, but when you put it all together with the Lord’s help, the arrangement can be a thing of beauty.

As we all know, the flowers eventually wither and die, as do we. Remember that our time is short, so enjoy the beauty of the intentional and the wildflower. This places us on higher ground.