Plant owners know just how difficult it can be to figure out what they need, especially when leaves start browning or wilting. But it turns out that plants may have been telling you all along. A new study found that when plants are stressed, they emit specific sounds that identify what's wrong. Previous studies had shown that plants vibrate when under stress, but for years, scientists have debated whether those vibrations become sound waves. By studying tomato and tobacco plants in an acoustic chamber inside a greenhouse, researchers at Tel Aviv University discovered that it's true – plants cry out...