Scenes of Masden first encountering the children were filmed in the English village of Turville in Buckinghamshire. This photogenic village is best known as the setting for the English sitcom The Vicar of Dibley (1994), but also appears in numerous other TV shows including Inspecteur Barnaby (1997), Jonathan Creek (1997), A Murder is Announced (1) (1985), Bonne nuit monsieur Tom (1998) and most recently Killing Eve (2018). It is also overlooked by the Cobstone windmill which is featured in Chitty Chitty Bang Bang (1968).
The story plays out over six years in the book in spite of the title.
Based on John Wyndham's novel, by 1981, it had sold over a million copies in Penguin Books. It's been translated into several languages. Wyndham wrote the novel in 1951 but by 1981 it had been reprinted 34 times.
Triffids can be tricked into thinking someone's gotten out of range if they stay quiet enough.