Have you ever described someone as a couch potato or called a dud car a lemon? How do you think this makes a potato or lemon feel? Tiffany find out its not fair to the plants. But there are people who are really nasty to plants - the Topiary Twins, Nettle and Thistle. They do dastardly things. They even keep some plants captive. They are villains of the worst kind.

Tiffany encounters Bindi and Dusty Thorn who own a green ambulance that they use to rescue endangered or neglected plants. They rush their ‘patients’ to their recovery hothouse where they nurse them back to health. Tiffany’s admiration for their dedication grows when she gets caught up in a showdown with the evil Topiary Twins - Nettle and Thistle.