Lily Whelehan, CC BY-NC-NDHow does the type of music affect plants growth? – Thomas, 14, Auckland, New ZealandWhen I’m in the lab studying my plants, I love to listen to music. But do my plants like it too, or do they just want some peace and quiet? It turns out plant lovers have wondered the same thing for nearly 70 years. And there are many albums and playlists for people to play to their plants. One of the most famous (and my favourite) is Mother Earth’s Plantasia. It was released in 1976 – “for plants and the people who love them”. Some people may think it’s nice to listen to music with their plants. But is there any truth to the idea that certain music boosts plant growth? Let’s dive into the science. Where did this idea come from?One of the most well known studies on music and plants was published by author Dorothy Retallack in 1973. It was a book called The Sound of Music and Plants. Retallack did several experiments playing music to plants. She reported that rock music made her study plants die, while classical music made them flourish. However, she was actually a music student with very little training in the scientific method. Her results were not peer reviewed, and the work was strongly criticised by the scientific community. Nevertheless, the story was widely publicised. A related book, titled The Secret Life of Plants, was also published in 1973. It covered multiple aspects of plant “intelligence”. A documentary of the same name aired in 1979. It featured incredible stories, such as that of a cactus that could speak Japanese. Despite being scientifically dubious, these ideas flourished in the alternative movement of the 1970s.Recent developmentsIn the decades since, many more studies have been published looking at the effect of music on plants. Many continue in the same vein as Retallack’s work, measuring effects of different types of music on plant growth. But the quality of these studies is also questionable. For example, some report statistical differences where there are none, do not include any statistical analysis, or are missing important parts of the methods. Other studies also focus on the effect religious music or chants have on plant growth, and contain strong religious language. This suggests some biases in how the studies are designed.Other studies are more robust in their methods. They have sound statistical methods, compare sounds other than music, and discuss possible effects of sound wave vibrations. However, since there is no evidence that plants have any ability to distinguish the subtle differences that define genres of music, the general consensus is that any research testing the effect of different types of music is inherently biased. Plants and soundAs in many cases in science, I think the true relationship between plants and sound is more interesting than the myth. Plants haven’t evolved to appreciate music as humans have. But the world has always had sound. So what does the world sound like to a plant? Plants evolved on Earth more than 850 million years ago, in the form of single-celled organisms that could harvest energy from sunlight. By 390 million years ago – what’s known as the mid Devonian period – plants had evolved into what we would recognise today as ferns, with structures such as roots and leaves. At this time, plants might have been exposed to sounds such as the munching of insects, thunder, rain, and running water. While our experience of sound is through the human experience of hearing, from a physics perspective, sound is simply waves of pressure. These pressure waves, or sound waves, interact with the physical environment as they pass through it. Studies have found that sound waves interact with plant structures such as leaf hairs. This shows plants can sense sound, without actually “hearing” it in the way that we might imagine. Researchers have also found that some plants will grow towards the sound of running water if it is played over speakers. Some plants had an improved predator defence response after they were played the sounds of insect predators.On the other hand, some human-generated sounds have been found to have a negative effect on plant health.So it’s possible that music could affect plant growth – if it happens to align with wavelengths and rhythms that mimic sounds the plant has evolved with, such as running water. However, because plants are highly varied and have evolved in different environments, if a certain music happened to improve growth in one species, it is unlikely to have the same effect on another species. As for me, I’ll continue listening to music in the lab. But I won’t worry about whether my plants will judge my taste.Lily Whelehan receives funding from the Australian Research Council.