To finance Mark Wallington's dream of being a television comedy writer, he becomes a gardener to the residents of north London for a year. He gardens for people like Mrs Fleming, convinced that there is buried treasure in the bottom bed; Mr Nugent, who saves his urine in jam jars to treat his compost; and Mr Walters who is trying to create a fascist state policed by gnomes in his plot. As Wallington crosses Hampstead Heath from job to job he survives brushes with the evil contract gardeners intent on knocking him off his bicycle, and falls for an actor named Helen. His nights are spent writing unsolicited scripts, and his days trying to understand the British and their strange obsession with gardening.