In an experiment run over a month, they found that tomato plants grew up to two inches taller if they were serenaded by the dulcet tones of a female rather than a male.
he findings vindicate comments made by Prince Charles that he talks to his plants although they suggest that for maximum results he would be better off recruiting the Duchess of Cornwall.
Appropriately the most effective talk came from Sarah Darwin, whose great-great grandfather was legendary botanist Charles Darwin, one of the founding fathers of the RHS' Scientific Committee.
She read a read a passage from the On the Origin of Species and beat nine other 'voices'.
Her plant grew nearly two inches taller than the best performing male and half an inch higher than her nearest competitor.
Colin Crosbie, Garden Superintendent at RHS, said: "We predicted that the male voice would be more effective but it turned out that the ladies were far better than the gentlemen.
"We just don't why. It could be that they have a greater range of pitch and tone that affects the sound waves that hit the plant. Sound waves are an environmental effect just like rain or light."
The experiment began in April at RHS Garden Wisley in Surrey, with open auditions for the public to record excerpts from John Wyndham's The Day of the Triffids, Shakespeare's A Midsummer's Night Dream and Darwin's On the Origin of Species.
A variety of voices was then picked to play to 10 tomato plants over a month. Every plant was played a voice through headphones connected to the plant pot, and the conditions for all the plants remained the same throughout the experiment. To ensure the experiment was fair, two control plants were also left to grow in silence.
The results showed that women on average saw their plants rise by an inch on their male counterparts. Some men were so bad that their plants actually grew less than a plant that was left completely alone.
Miss Darwin said, "I think it is an honour to have a voice that can make tomatoes grow, and especially fitting because for a number of years I have been studying wild tomatoes from the Galapagos Islands at the Natural History Museum in London.
"I'm not sure if it's my dulcet tones or the text that I read from On the Origin of Species 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."