EN
The experiment was carried out under field conditions. Five accessions were included in this study: Medicago sativa, Medicago media, Medicago falcata and interspecific hybrids Medicago falcata x Medicago sativa, Medicago falcata x Medicago media. The results showed that best source of germplasm of winterhardiness were Medicago media, Medicago falcata and hybrids Medicago falcata x Medicago sativa, Medicago falcata x Medicago media. The plants material derived from this study, possessed winterhardiness sufficient to use them in Polish climatically conditions.