I understand your thinking on what you said. By saying the tomatoes were just okay, you didn’t really win favor with her. If you had tweaked it just a bit and said, “They were delicious. I’ve only had friend summer squash before, which I really love.” This would have flattered her, and opened up the conversation, rather than ending it.

You didn’t say anything wrong. Just food for thought (pun intended ) for artful conversation skills in the future.