Lost in Space - Season 3 - Eps 23: The Great Vegetable Rebellion
Doctor Smith uses the Space Pod to land on a planet that the Jupiter II is passing by. It turns out that the planet has evolved in such a way that plants are the highest form of life, and some of them are quite intelligent. One of these plants, a large carrot, captures Smith and tries to change him into a plant. The Jupiter II lands and the Robinsons and West come to Smith's rescue, only to be captured themselves. Eventually they thwart the plant creature and make their escape.
About Lost in Space

Title: Lost in Space
First Air Date: 1965-09-15
Last Air Date: 1968-03-06
Status: Ended
Rating: 7.1/10 (from 115 votes)
Language: EN
Seasons: 4
Total Episodes: 83
Network: CBS
Genres: Sci-Fi & Fantasy, Comedy
Production Companies: Irwin Allen Productions, 20th Century Fox Television
Synopsis
The space family Robinson is sent on a five-year mission to find a new planet to colonise. The voyage is sabotaged time and again by an inept stowaway, Dr. Zachary Smith. The family's spaceship, Jupiter II, also carries a friendly robot who endures an endless stream of abuse from Dr. Smith, but is a trusted companion of young Will Robinson
Cast

Guy Williams
Dr. John Robinson

June Lockhart
Dr. Maureen Robinson

Mark Goddard
Major Don West

Marta Kristen
Judy Robinson

Angela Cartwright
Penny Robinson

Bill Mumy
Will Robinson

Jonathan Harris
Dr. Zachary Smith

Dick Tufeld
Robot B-9

Bob May
Robot B-9