Sweet-Ark® Immaculate is a new, late-season, floricane-fruiting, thornless blackberry variety. This new variety has good yield potential comparable to Osage and Sweet-Ark® Caddo. Berries are medium-large and very firm, with postharvest potential similar to Ouachita and Sweet-Ark®Caddo and slightly superior to Osage and Sweet-Ark® Ponca. Fruit of Sweet-Ark® Immaculate is expected to perform comparably to other Arkansas blackberry cultivars for storage and shipping. In Arkansas, the first harvest date is June 26, 11-12 days after Osage and Sweet-Ark® Caddo. Sweet-Ark® Immaculate is intended to be a complement to Navaho and Von in late season fresh market blackberry production