Stressed Plants Are Literally Crying Out for Help, New Research Finds

We love our houseplants. We talk to them; we try to give them the best possible light. We even play music for them. But we’re not perfect, and sometimes despite our best efforts, our plant babies still wither and die. If you ever wish your plants could actually communicate and let you know what’s wrong, you’ll be interested to know that researchers recently made the discovery that those suffering plants may be literally crying out for help.

In the scientific journal Cell, scientists reported that stressed plants emit ultrasonic airborne sounds that carry information about how they’re doing. These sounds varied from clicks to pops (reminiscent of popcorn popping or bubble wrap being compressed). Not only that, their research showed the studied plants produced different noises based on why they were stressed. For example, thirsty plants cried out differently than cut plants. These sounds could be detected from 3 to 5 meters (about 9 to 16 feet) away by mammals and insects with sensitive enough hearing (such as mice and moths).

“In this study, we resolved a very old scientific controversy: We proved that plants do emit sounds!” said Professor Lilach Hadany, who led the study, in a YouTube video posted by Tel Aviv University. “Apparently, an idyllic field of flowers can be a rather noisy place. It’s just that we can’t hear the sounds.”

Plants obviously don’t have vocal cords; it’s suspected that the sound is created by cavitation—a term used to describe how bubbles or voids in liquid behave and move. Cavitation is the reason you hear a popping sound when you crack your knuckles.

What causes plants to cry out?

What’s the reason behind these cries for help? That’s yet to be determined, but there is some definite curiosity in the plant community about what plants are communicating to each other and their surrounding ecosystem. The findings could also have a profound impact on agriculture.

“Our findings suggest that the world around us is full of plant sounds,” Hadany said. “We believe that humans can also utilize this information, given the right tools, such as sensors that tell growers when plants need watering.”

Specifically, scientists are hopeful the studies will help them more accurately measure agricultural water needs on a grander scale. In the meantime, we'll be picking up and propagating a few more plants so they can all keep each other company.