Interest in the cultivation of kelp is increasing in the north of Norway. In the present study, Saccharina latissima was cultivated at two sites (Kraknes and Rotsund), 90km apart, in Troms, northern Norway (69-70 °N) in 2020. The effect of site, depth and sori origin (Kraknes and Rotsund) on S. latissima growth and mineral content was studied. Large variations in the frond length and wet weight were observed between sites. The site with lower seawater temperature and no fresh-water influence had better growth and later outbreak of epibionts. Sori origin also had a significant effect on the growth, S. latissima produced from Kraknes sori had higher frond length and wet weight irrespective of grow-out site and grew best at their own site. This indicates inherent genetic difference in growth traits, as well as local adaptation to the natal environment for optimal growth.  The iodine content in general was high and increased with cultivation depth, and the results showed lower iodine content at the freshwater influenced site (Rotsund). The heavy metal content varied significantly between sites and sori origin and were lower than the recommended maximum level for food supplements in EU regulations. The present study shows that both growth and mineral content vary profoundly within the same geographical region and it thereby underlines the importance of thorough site selection and using local traits with high growth rates for seeding and cultivation to achieve maximum biomass, higher quality and economic viability.