According to a recent study, published in Cell, thirsty or stressed plants make sounds that can be heard up to several metres away.
Plants that need water or have recently had their stems cut produce up to 35 sounds per hour, while well-hydrated and uncut plants only make about one sound per hour.
At ultrasonic levels (20–100 kHz) few humans can hear them, but some animals, such as bats or moths, may be able to.
Researchers from Tel-Aviv University in Israel recorded the sounds which are like short clicks and it’s thought these are made by the xylem, the tubes that transport water and nutrients from the plant’s roots to their stems and leaves. And it wasn’t one particular type of plant that made the noise: tobacco, tomato, wheat, maize and vines all made noises when they needed water.
Reading the research we couldn’t help but be reminded by Roald Dahl’s story The Sound Machine…