ProFlowers says that some scientists and researchers have found evidence that plants do indeed react to a number of environmental stimuli, including vibrations. Sound is considered a form of vibration, so it’s not too far-fetched to think that sound could have some kind of effect on plant growth. However, some scientists believe plants evolved to respond to vibration so that they could survive even in windy conditions.

Penn State University also covered this idea of plant growth in some depth. They caught up with Rich Marini, head of Penn State’s horticulture department. He said:

…there is evidence that plants respond to sound. Wind or vibration will induce changes in plant growth. Since sound is essentially vibration, my guess is that vibration is causing response. – Rich Marini

There is also a 2007 paper from scientists at South Korea’s National Institute of Agricultural Biotechnology that proposed that two genes involved in a plant’s response to light are turned on by music played at 70 decibels, which is about the level of a normal conversation according to Marini. What the Korean researches found was that there was a different response from the plants depending on the frequency of the sound. The higher the frequency, the more active the response.

Marini also backs up the idea that a plant’s response to vibration may have been a matter of survival. According to Marini:

Plants exposed to wind produce a growth-retardant hormone called ethylene, which causes the plant to be shorter and to have thicker stems. So plants exposed to wind can better survive very windy conditions. – Rich Marini

Naturally, there is a common sense element to plant growth. You must provide them with the light, water and mineral nutrition they need to grow.