My wife is trying to recall the title of a story. A suburban house becomes overgrown with vegetation, and eventually we learn that the people living in it became plants. She remembers the story, but not the title.
The title contains the name of the family in question. It’s “Whatever Happened to the Andersons?” or “Whatever Happened to the Robinsons?” or something like that.
When I put the phrase “Whatever Happened to the” in it, I only get one story, “Whatever Happened to the Olmecs?” by Kate Wilhelm from 1973. That doesn’t seem to be the story you’re looking for. Then I tried a slightly different phrase. The story that came up in the search was “Whatever Became of the McGowans?” by Michael G. Coney from 1972, which may be the one you’re looking for: