An Etymological Dictionary of the German Language/Annotated/Wirsching
Wirsching, Wirsing, masculine, ‘borecole,’ first recorded in Modern High German; the word seems, however, to have been borrowed at an earlier period from Upper Italy, as is also indicated by the French term, chou de Milan ou de Savoie. It is based on Lombardic versa (compare Italian verzotto), ‘cabbage, borecole,’ which is usually referred to Latin viridia, ‘vegetables.’ Kohl and Kappes were borrowed at a much earlier period.