This is a great thread ! I am working on a traveling show at the moment on the history of flower pots in the Americas and Britian .We are calling the show " A Place To Take Root "
             I brought up this subject with Peggy Cornett who is the plant historian at Monticello and who spoke at the third weekend when the show was at Stonington Ct , and she said much of the same thing that she thought the making of emotional imagery of this kind was a Victorian addition. It does seem like something that would have been around in Elizabithian times and back to Greece and Rome !