S44E3: Talking Trees

Can a plant, something without a mouth, ears or eyes, communicate? Yes! Plants do communicate but not in ways that are obvious to humans. Instead of barking or shrieking when they are attacked, they release chemical ‘signals' into the air which can be detected by other plants. But these physical and chemical defences cost energy that could be used to grow instead of being used for protection. Do they protect themselves, or grow?