New Study: Your Houseplants Might Literally Be Crying for Help

Israeli researchers just released a new study showing that plants make tiny sounds when they’re stressed. The sounds, which can only be heard with the help of ultrasonic microphones, resemble quiet “pops” or clicks. The researchers found that whenever they cut a plant, under-watered it, or otherwise subjected it to stress, the plant would emit sounds much more frequently.

The plants’ tiny pops, therefore, “might be their version of a call for help,” The Washington Post reported.

The scientists’ research took six years to conduct. They tested a wide range of species, including tomato plants, cacti, tobacco plants, and grape vines. Different plants seemed to speak different languages. Each type of plant had its own frequency and volume of pops.

It’s possible that some animals, like bats and mice, can hear these sounds, reports Scientific American. Other research has also found that plants seem to “hear” and respond to certain animal sounds. This research might be evidence that there’s a lot more complex ecosystem communication going on beyond the scenes. Still, that’s yet to be proven.

Plants communicate in other ways

While the findings of the experiment were pretty novel, they shouldn’t come as too much of a surprise. After all, plants communicate their stress in plenty of other ways.

When subjected to insects or drought, many trees send signals through their roots or through underground systems of fungi. Other leafy plants emit certain gases. The gaseous chemicals provide a form of communication, signaling to other plants that there may be an incoming threat. When a sick plant releases these chemicals, neighboring plants begin amping up their internal defenses to prepare for the potential threat. (Some of these airborne chemical compounds may also help boost human immune systems.)

Even more interesting: “Plant vibrations have been described in several scenarios,” the study adds. “Plants exposed to drought stress have been shown to experience cavitation — a process where air bubbles form, expand and collapse…causing vibrations.”

The ultrasonic sounds are caused by a similar process: the popping of tiny air bubbles within a plant’s tissue.

Are they really crying for help?

It’s hard to say whether the plants are “intentionally” using the sounds to communicate with one another, or if it’s just an interesting side effect of physiological changes that happen within a stressed plant. So, at this point, the “cry for help” theory is a bit of an exaggeration. (Though, those of us who struggle to keep a houseplant alive will certainly that it resonates.)

Still, this research is just the beginning, the researchers say. As they conduct more experiments, they might discover even more complexity in plant communication. So, don’t give up on that houseplant just yet. You never know what it might be “thinking.”