A trial conducted by Güizzo Frutas Frescas S.A. in Jujuy, Argentina, in partnership with Dr. Viviana Curzel and producer Oscar Machuca, has led to the first harvest of stone fruits, including the Royal Lee variety, several weeks earlier than usual, on September 24. The trial, which started in 2022, is focused on early production varieties of cherries, peaches, nectarines, and plums, and is aimed at advancing the harvest window in northern Mendoza from weeks 42/43 to weeks 39/40. The results show promise for achieving harvests as late as the last week of September, given the region's optimal conditions for ultra-early stone fruit production and its unique climate. The research also highlights the potential of new genetic developments of cherries with low cold requirements, such as those from the Bloom Fresh, SMS, and Zaiger genetic programs, for adaptation in the region. Future challenges include optimizing agronomic management and identifying more adaptable varieties for the area.