Back in 1848, the German professor Gustav Fechner published the book "Nanna (Soul-life of Plants)", popularizing the idea that talking to plants is good for them and helps maintain health and growth. While studies have shown that plants respond in some ways to sound, the necessity of having conversations with them is still not deemed as important as watering and good sunlight.

Nevertheless, some growers swear by the technique — including one famous British royal by the name of Prince Charles. "I happily talk to the plants and trees, and listen to them. I think it's absolutely crucial," the prince says in a new BBC documentary. "Everything I've done here, it's like almost with your children. Every tree has a meaning for me."

Of course, the 61-year-old is well-known for his commitments to the environment and organic gardening, most recently wrapping up his Garden Party to Make A Difference at Clarence House. He mentions, however, that before environmentalism reached the level of acceptance it has today, his passion was considered something of an oddity.

"I got a lot of flak for a lot of things," Charles says in the film. "I mean, potty this, potty that, loony this, loony that."

The full documentary on the Prince of Wales and his home, Highgrove House, airs this week on BBC Two.

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.

Prince Charles enjoys talking to his plants
Royal admits in new BBC documentary that many people considered him 'loony' before the modern environmental movement became hip.