When asked where Seymour got the plant, he replies that the seeds were obtained by a Japanese gardener who found the bulb in a "plantation next to a cranberry farm." This joke is lost on modern audiences. In 1959, it was announced that cranberry crops were tainted with traces of the herbicide aminotriazole, and as a result, cranberry sales plummeted.
A young Jack Nicholson has only a small part.as Farb's masochistic patient, Wilbur Force. Later, however, as the actor's career began to take off, he was prominently featured on the home-video releases to help generate interest in the film.
Charles B. Griffith stood off-screen providing the voice of Audrey Junior as a reference for the actors. The voice of the plant was supposed to be dubbed in by another actor in post-production, but Griffith's vocalization of the plant got laughs--and director Roger Corman was notoriously cheap--so his voice remained in the final print of the film.
Charles B. Griffith put several of his relatives in the film; Myrtle Vail--"Grandmother" Myrt --for example, is actually his grandmother, and the hobo who Dr. Farb tortures in his office is Griffith's father. He also placed several of his relatives in crowd scenes. The bums in the background of the street shots on Skid Row are real transients, however, and were filmed in the actual skid row area of Los Angeles.
Charles B. Griffith not only wrote most of the screenplay, he also stars--uncredited--as several characters, among them: the screaming dental patient who runs out of Dr. Farb's office, the burglar who breaks into the flower shop, and even the voice of Audrey Jr.
The manager of Producer's Studio informed Roger Corman that a large office set had been constructed for a production that was about to wrap. Corman arranged to use the standing set, redressed, as the main set of this film.