The purpose was to study the adaptive capabilities of beech seedlings, obtained in laboratory and solarium conditions from seeds of origins Nitra, Slovakia (collection 2019) and Humosu, Romania (collection 2020) and transferred to natural growing conditions in the “Plaiul Fagului” Scientific Reservation Republic of Moldova. Before stratification, the seeds were treated with various natural bioregulators (Moldstim, genistifolioside, RNC3); and germinated seeds were sown in an IGPPP solarium. During the growing seasons 2020-2021, plants were treated several times with the same bioregulators. In the early spring of 2022, seedlings Nitra-19 (3-rd year of growth) and Humosu-20 (2-nd year of growth) were transferred to the “Plaiul Fagului” Scientific Reservation. Monitoring of adaptation, growth and development of beech seedlings carried out over two seasons showed the different ratio of adaptation and survival of plants, as well as their mophobiological characteristics, depending on the origin of the seeds, bioregulators application and the age of transferred plants. The ratio of surviving seedlings was 58.38% and 37.91%, respectively for Nitra and Humosu origin. At the end of September 2023, the plant height varied from 16 to 102 cm in Nitra and from 12 to 85 cm in Humosu plantation. Research was carried out within the Scholarship grant #51700164 (2023-2024), financed by International Visegrad Scholarship Fund and within the State Program no. 20.80009.7007.07, financed by the National Agency for Research and Development of the Republic of Moldova.