In a study performed by the Royal Horticultural Society, researchers discovered that talking to your plants really can help them grow faster. They also found that plants grow faster to the sound of a female voice than to the sound of a male voice. Other studies have experimented with different sound levels and even the kinds of things that are said to plants—do they respond better to compliments or insults?
Royal Horticultural Society Study
In the month-long study, the Royal Horticultural Society recorded 10 people, including both men and women, reading from either literary or scientific works. Each recording was played through a set of headphones that was attached to each tomato plant's pot (so, one tomato plant per person). The same tomato variety was used, same soil, same care regimen, etc. They also included two plants that were not read to as a control.
At the end of the month, the plants that had been attached to female voices grew an average of an inch taller than those attached to a male voice. The overall winning tomato listened to Sarah Darwin, great-great-granddaughter of Charles Darwin. Her plant grew approximately two inches taller than the rest.
What Did Ms. Darwin Read to Her Tomato Plant?
Asked about her plant's favorable response to her voice and selection, Sarah Darwin commented, "I'm not sure if it's my dulcet tones or the text that I read from On the Origin of Species [her ancestor's seminal work] that made the plant sit up and listen, but either way I think it is great fun and I'm proud of my new title."
Researchers went into the RHS study with the idea that the male voice would make the plants grow faster, and they were surprised by the results. They said that they are unsure why the female voice worked better, positing that it could be related to women's greater range of pitch or tone that affects the sound waves that hit the plant, and that sound, just like any other environmental factor, has an effect on plant growth.
The results of the RHS study have been supported by other studies and theories, yet the exact link between the human voice and plant growth remains elusive. Here are a few other studies and findings of interest:
- The TV show "Mythbusters" conducted a study in which 60 pea plants were divided among three greenhouses. In one greenhouse they played recordings of humans saying nice things to the plants. In another, recordings sounded insults at the plants. The third greenhouse was silent, with no recordings played. After two months, the pea plants showed greater—but roughly equal—growth in the two greenhouses with the recordings, and they showed the least growth in the control greenhouse with no sound.
- Researchers with the National Institute of Agricultural Biotechnology in South Korea found that plant growth is stimulated by music, and the growth appeared to be linked to two genes related to how plants respond to sunlight.
- Charles Darwin himself suspected a link between plant growth and vibration. In an informal experiment, he had his son play the bassoon to seedlings, but the results were inconclusive.