Can Plants Hear?

When I was a kid, I remember reading that plants grow faster if they hear classical (Western) music. Turns out those claims “have never been substantiated by rigorous experiments,” says Richard Karban from the University of California at Davis. Ed Yong says those unscientific, yet hugely popular claims weren’t just wrong; they did damage:

“They tainted the entire field of study, making scientists skeptical about the very notion of plants exchanging signals.”

But now two researchers in Israel, Lilach Hadany and Yossi Yovel, have found that plants can hear the sounds of pollinators (aka bees). You may be wondering how someone could possibly know that, right?

“In both lab experiments and outdoor trials, they found that the plants would react to recordings of a bee’s wingbeats by increasing the concentration of sugar in their nectar by about 20 percent. They did so in response only to the wingbeats and low frequency, pollinator-like sounds, not to those of higher pitch.”

Further:

“And they reacted very quickly, sweetening their nectar in less than three minutes. That’s probably fast enough to affect a visiting bee, but even if that insect flies away too quickly, the plant is ready to better entice the next visitor. After all, the presence of one pollinator almost always means that there are more around.”

Keep in mind these results haven’t yet been published in a scientific journal. Put differently, it means these results haven’t yet been vetted and approved by peer scientists. But Yong feels these claims more likely to be true than the ones on growing faster when exposed to classical Western music. Why?

“Here, the plants’ responses make clear evolutionary sense. Sweeter nectar is more enticing to pollinators, and by attracting more pollinators, the plant increases its odds of making more plants.”

As opposed to:

“It’s a far cry from past studies that showed plants reacting to sounds they would never normally encounter, such as classical music.”

Of course, it’s better to wait for peer confirmation and independent verification of the results. That said, if this turns out to be true, it may answer that old Zen question once and for all!

“When people pose the old question about whether a tree falling in an empty forest makes a sound, they presuppose that none of the other plants in the forest are listening in.”