Red fescue (Festuca rubra L.) is a perennial plant of the cereal family (Poaceae), which is used as a fodder and lawn crop. Despite substantial research, the number of high-yielding varieties adapted to specific soil and climatic conditions is insufficient. Therefore, the examination of the genetic diversity of red fescue plants is the main stage in the creation of new varieties. The purpose of the study was to evaluate samples based on the main economic-biological characteristics and divide them into three groups of ripening for further use in breeding as a source of valuable traits. The study used general scientific (analysis, synthesis, experiment, description, observation, and comparison), field (phenological observations and accounting), and statistical methods. According to the results of the study, populations of different ecological and geographical origins created by different breeding methods were similar. The coefficients of variation in the parameters of the main features were in the range of 0.34-8.02% and depended on the biological and ecological characteristics of the samples. According to the duration of the growing season, the samples were divided into early-ripening (16 pcs.), medium-ripening (20 pcs.), and late-ripening (12 pcs.). When clustering by eight features, all samples were divided into three clusters. In the early-ripening group, substantial correlations were established between the duration of the growing season and 1000 grain weight, between plant height and seed yield, and between dry matter yield and leaf colour intensity. Positive associations between dry matter yield and regrowth intensity, between 1000 grain weight and leaf colour intensity were observed in the middle-ripening group. In the late-ripening group, reliable relationships were identified between plant height and tillering intensity, seed yield and 1000 grain weight, seed yield and leaf colour intensity, and dry matter yield and leaf colour intensity. The results obtained will be used in further breeding work when creating varieties of red fescue of various ripening groups with improved seed productivity, suitable for fodder and lawn use
