Dame Emma Thompson said that it took her nine years to write this screenplay, while it took her only five years to write Raison et sentiments (1995), for which she won an Oscar.
The location of the Brown's family house was just a huge muddy field covered in brambles. The crew had to bring in items and sets to build all of the village, the house, the tracks, the garden, and the trees.
When Celia Imrie puts a worm into her mouth, it was not a prop nor a special effect. She really did put a worm in her mouth and seemingly chew it, only to spit it out after the shot was in the can. No worms were harmed in the making of this movie.
The village and the Brown house had to be built from scratch. One of the reasons for this was so the production wasn't troubled by modern items like power lines coming into view.