Stories from the set

In the end credits, immediately after the main cast, 118 plants featured in the film are listed.

The film's first screening took place under the canopy of a ginkgo tree growing in the Marburg Botanical Garden.

Ildikó Enyedi wrote the character of Dr. Tony Wong specifically for Hong Kong actor Tony Leung Chiu-wai after watching recordings of his interviews. Despite the producers' doubts, after receiving the script the actor called the director online and said: "I agree."

For Hong Kong actor Tony Leung Chiu-wai, "Silent Friend" became the first European film in which he starred.

Preparing for the role of the scientist, Tony Leung Chiu-wai studied literature on cognitive development in infants, visited three universities, talked with neuroscientists, and worked with an English teacher to put on a British accent. Preparation for the role took six months.

Director and co-screenwriter Ildikó Enyedi nurtured the idea for the film for more than twenty years.

The film is dedicated to the memory of German producer Karl Baumgartner, who helped Ildikó Enyedi work on the film back in the 2010s and was its first producer.