Let me be the first to post on this forum. Porretta is not my last name, but my husband's. His family hails from Sora, Italy. Here is a surname history from the Historial Research Center, which is a start:
"The Italian surname Porretta is of toponymic origin. A surname of this type derives from a place-name where the original bearer resided or held land. In this instance the surname derives directly from the place-name Porretta. In the Middle Ages the pattern serving as a basis for fixed Italian surnames was based on paternity, but before the advent of a structured system of surnames, a man was most conveniently identified by his place of abode. The town of Porretta is located on the Apennines Mountains between Florence and Bologna, and is famous for the thermal waters. These springs have been known for a long time, at least from the time of the Romans and they are supposed to cure the ailments of the throat and lungs.
Another origin for this surname is proposed by the Italian-American scholar Joseph G. Fucilla, an authority on Italian surnames; Porretta could derive from the term "porro," meaning "leek." In a mainly agricultural society, it was easy to find names deriving from garden vegetables: lacking regular surnames, the name of the product someone was cultivating was a suitable means to recognize him. The suffix "-etta" of the surname Porretta, is one of those suffixes such as "-ino," "-one," and "-ello" which give a particular flavour and meaning to nouns and adjectives to which they are attached. Since the Middle Ages, they were and are used with first names to indicate size, age, affection, physical, and moral qualities.
Variants of the surname Porretta are Porrata, Porrini, and Porro. References of the surname or of one of its variants mention a family by the name of Porro listed in the nobility of Milano. Records show that in the eleventh century this family owned many fiefdoms in Lombardy."
Blazon of arms: Azure, three leek plants proper, placed in fess, the roots in chief; a chief or charged with an eagle issuing sable.