I would suggest this could be either an episode of The Space Sentinels shown on British TV in the late 1970s and early 80s or an episode of Battle of the Planets.
The space sentinels had a cast of three main characters. One was a girl and there was definetly an episode revolving around plants growing out of control. Memory does not allow me to be more detailed than that sadly.
The Battle of the planets episode sounds more likely to me though. It was a Japanese anime, original title being Gatchaman. Th episode with the plants is actually a two parter called Fierce Flowers (Attack of the Jigo Killers in the original Japanese). The plants are vaguely Venus fly trap shaped, one character is female and does own a restaurant although this is peripheral to the story. I will update this answer with links if I can find the relevant clips on YouTube