Peter Bromhead: Cursing at weeds will only help them

Prince Charles, who more than two decades ago admitted talking to plants, and Camilla, Duchess of Cornwall, in their garden at Birkhall, Scotland. Photo / AP

Scientists have found plants may have a secret language and thrive on a chat, even if it’s an insult

When Prince Charles admitted in 1986 that he enthusiastically talked to his garden plants, this was perceived by British media as just another example of dotty eccentricity expected from someone whose family lineage had been subjected to centuries of inbreeding.

When asked again last year in a BBC Countryfile interview if he still conversed with flowers he jokingly responded, "Not only talk, but instruct them."

Certainly, nobody can scorn the Prince of Wales' efforts to champion organic and sustainable farming on his Highgrove Estate in Gloucestershire or his personal deep-rooted respect for nature and if some of his methods seem slightly unconventional, but work well in practice, who cares?

Illustration / Peter Bromhead

The fact is, talking to your garden plants may not be as daft as first perceived.

When the television show Mythbusters examined the power of words on vegetation they came up with some surprising results. The team procured 60 pea plants and divided them into three greenhouse groups. They then recorded two soundtracks, one full of praise for plants and the second a tirade of insults and played them repeatedly to the pea plants in separate greenhouses. A third greenhouse remained silent as an experimental control.

The team charted the plants' growth over 60 days to determine the winning greenhouse by comparing plant masses from the three groups. The results were surprising; the silent greenhouse performed poorest, producing lower biomass and smaller pea pods than the other two. There proved to be no difference in plant quality between the praise and insult greenhouse - the soundtracks seemed to produce a positive effect in both. The finding from the normally sceptical showmen suggested there appeared to be benefits to plants being subjected to audio frequencies and declared their resulted findings as plausible.

This also confirmed a respected South Korean scientist's findings in 2007 that playing music to rice plants speeded up the growth and blossoming of the plants.

Back in Britain, scientists at Bristol University have been carrying out a series of experiments using powerful loudspeakers to listen to corn saplings and their findings confirm that they have recorded a series of clicking sounds coming from their roots.

When they suspended their roots in water and played a continuous noise at a similar frequency to the clicks, they found the plants grew towards it. The scientist suggests this is evidence that plants may have their own language of noises, inaudible to human ears and believe that sound and vibration may play an important role in the life of plants.

A paper released recently from the Spatial Industries Business Association throws further light on the mystery when reviewing the work of researchers at Massachusetts Institute of Technology (MIT), Microsoft and Adobe who have developed an algorithm that can use spatial analytical methods to reconstruct an audio signal by analysing minute vibrations of objects depicted in video. In one set of experiments, they were able to recover intelligible speech from the vibrations bounced back from the leaves of a potted plant.

"When sound hits an object, it causes the object to vibrate," says Abe Davis, a graduate student in electrical engineering and computer science at MIT and first author on the new paper.

"The motion of this vibration creates a very subtle visual signal that's usually invisible to the naked eye. People didn't realise that this information was there." I personally listened to an experimental bounce-back recording of Mary had a little lamb, from the leaves of a plant, caught on high-speed video and was surprised at the clarity of the reflected returning sound. These experiments suggest that plants are sensitive to vibration beyond the hearing of the human ear and may be the reason why the pea plants did so well in the Mythbusters experiments. They clearly respond positively to human voice vibration, even if oblivious to the subtle difference between insult and praise.

So will I join Prince Charles and commence prattling to my garden plants?

Well, I've made a note to stop cursing at weeds growing profusely at the expense of everything else. Clearly my insults are only encouraging growth as expletive vibrations reign down every time I approach my vegetable patch.