The citrus grove is one of the oldest areas of the Botanical Garden. It was created by Michele Tenore at the request of the Bourbons, who greatly appreciated the trend, fashionable ate the time, of displaying collections of archaeological and (as in this case) naturalistic artifacts to be shown to their guests. To follow this trend, the Bourbon rulers suggested to the first director of the Botanical Garden the establishment of a collection of citrus fruits that included both food related plants and varieties with a distinctive appearance that were appreciated from an ornamental point of view.
The collection of citrus fruits was later expanded by Giuseppe Antonio Pasquale and further enriched in recent times. Among the most interesting entities currently present in the citrus grove, we mention the varieties of bitter orange (Citrus aurantium) and pomelo (Citrus maxima) with their "monstrous" characteristics, some species such as Citrus volkameriana and Severinia buxifolia, which were first described by Neapolitan botanists, and representatives of genera related to Citrus, such as Poncirus, Microcitrus, and Fortunella. Also represented are the species from which all cultivated citrus fruits originated.