Why does Dickens compare Wemmick to a gardener when he walks among his prisoners in Chapter 32 of "Great Expectations"?
As Wemmick takes Pip on a tour of Newgate Prison, he strolls among the inmates, noting "the advance they had made, since last observed, towards coming out in full blow at their trial". The lawyer is concerned but impersonal, and his manner in making his rounds reminds Pip of how a gardener might act in walking among his plants.
Mr. Wemmick first notices "a shoot that had come up in the night" in the person of a new prisoner who had not been there the day before, then he catches sight of another prisoner he has not seen in two months, peeking out from "behind the cistern". As he continues to walk through his "greenhouse", he acknowldeges "his personal recognition of each successive client...in a nod", just as a gardener might give a cursory acknowledgment to each potted plant in his garden. Near the end of his visit, Wemmick spends a bit of extra time with the Colonel, a Coiner and "a very good workman" who is to be executed on Monday. He talks with the man, taking care of last minute details, then gives a final nod at his "dead plant" as he leaves, casting "his eyes about him in walking out of the yard as if he were considering what other pot would go best in its place" (Chapter 32).