By contrast, stressed plants are much noisier, emitting an average up to around 40 clicks per hour depending on the species. And plants deprived of water have a noticeable sound profile. They start clicking more before they show visible signs of dehydrating, escalating as the plant grows more parched, before subsiding as the plant withers away.

someone smarter than me should get to inventing a device that listens to plant clicks and tells you when it needs water