I remember when the height of horticultural wisdom was to talk to your houseplants to supposedly help them thrive. I used to joke with friends about taking this advice to heart. Then when my plants started answering me, I knew I needed to take a break and get out of the house. But according to a recent National Geographic article, the joke may be on me.

Think about it: To react to its changing environment, a plant must communicate with all its constituent parts. Leaves must be able to detect predators and changes in light, and roots monitor nutrients and water supplies. But instead of signals moving through nerves, it’s more like plumbing. Electrical signals can travel through chemical movements in those tubes, like roots telling leaves to limit transpiration because water is becoming scarce.

How do we know this? The same microphones that detect bat calls can pick up these plant sounds. Many species, from tomatoes to cacti, emit ultrasonic popping sounds when they’re stressed. These can be heard by insects and small mammals. If we can figure out exactly what these sounds mean, we’ll have a new tool to monitor plants without touching them.

And there are other ways plants can communicate with us, like using smell. They can release volatiles, gaseous chemicals which can be used to announce when flowers are ready for pollination, to discourage predators, or as a distress call, like signaling to carnivorous bugs in the area that a caterpillar is munching on a leaf. That familiar cut-grass small is actually a sign of distress.

The communication possibilities can actually get pretty complicated. For more detail, see “Plants Can Talk. Yes, Really. Here’s How.” by Allie Yang at https://www.nationalgeographic.com/science/article/plants-can-talk-yes-really-heres-how?