https://bazarow.com/recensie/middeleeuwse-tuinen/
I also found a nice book, about a former exhibition, which covered medieval gardens.
It has nice pictures of old gardens, and it explains something about the "Capitulare de villis" written by Karel de Grote in the 9th century.
https://en.wikipedia.org/wiki/Capitulare_de_villis#Land_and_food
https://de.wikipedia.org/wiki/Capitulare_de_villis#Liste_der_Pflanzen
https://de.wikipedia.org/wiki/Capitulare_de_villis#Liste_der_B%C3%A4ume
