The Casual Gardener: There's a renewed buzz about the benefits of talking to plants
New research suggests there may be some merit in talking to your plants
IF YOU sowed some sweet pea before Christmas and the seeds have duly sprouted, perhaps you fancy giving them a few words of encouragement? Or maybe it's time to chat up those tulip bulbs you planted in October in the hope that it gives them some added vigour come spring?
The idea that talking to plants in order to help them grow faster and stronger is nothing new. The heir to the British throne, no less, once claimed to be an advocate of talking to flora, telling BBC Countryfile in 2013 that he liked to give plants a little verbal encouragement.
The Prince of Wales's namesake Charles Darwin was also open to the possibility that plants respond to sound. Having initially noted that seedlings appeared to be sensitive to vibrations, Darwin had his son play the bassoon to see if the young plants responded. It wasn't the On the Origin of the Species' author's most celebrated experiment, however, yielding inconclusive results.
Recently, more rigorous experiments have found evidence that some sounds may cause subtle changes in some plants at different stages of their life cycles.
For example, it's thought that ultrasound, with frequencies higher than those in the audible spectrum, may enhance seed germination.
Experiments with young chilli plants have shown that they can sense the presence and identity of neighbouring plants, through some unconventional and as-yet-unidentified mechanism. It's thought vibrations may play a role.
One credible reason for plants responding to human voices is that talking – and singing too – produces carbon dioxide, the gas on which plants rely to photosynthesise.
However, one simpler explanation is that people who talk to their plants are more likely to take better care of them, watering and checking for pests and diseases with greater regularity.
Last week it was reported that Israeli scientists had found that some flowers can hear, and use the skill to listen for the buzz of a bee's wings.
Researchers at Tel Aviv University who made the discovery after playing recordings of bee buzzes to evening primrose flowers, say on hearing the buzz, the plants boosted the sugar content of their nectar but when played sounds at a higher frequency, like those made by a mosquito, the flowers did not change their nectar.
The researchers suggest that the sound of a bee makes tiny vibrations in flower petals that trigger the sugar response.
Professor Lilach Hadany, who led the study, said: "Our results document for the first time that plants can rapidly respond to pollinator sounds in an ecologically relevant way.
“We found flowers vibrated mechanically in response to these sounds, suggesting a plausible mechanism where the flower serves as the plant's auditory sensory organ.
"Both the vibration and the nectar response were frequency-specific. The flowers responded to pollinator sounds, but not to higher frequency sound."
However, Prof Hadany and her team said a plant's ability to respond to pollinators may be inhibited in city environments or beside a busy road.
"These advantages can be diminished in very noisy environments, suggesting possible sensitivity of pollination to external noises," she said.
While plants require water, sunlight and the right temperature to grow, it was widely believed they did not have senses in the way animals do.
But the study, published on the open-science website BioRxiv, suggests the efforts of gardeners who talk to their plants may not be in vain.
"Plants' ability to hear has implications way beyond pollination – plants could potentially hear and respond to herbivores, other animals, the elements, and possibly other plants," Prof Hadany added.