The rhythm of seasonal development and minor life cycle of Prunella vulgaris L., a long-rooted life form was studied in Khakasia. It was established that individuals formed spring and autumn leave generations and belonged to long-vegetated summer-chimochlorous plants. Observations of dicyclic mesorosular and fall monocyclic semirosular generative monocarpic schoots were conducted. The period of shoot development from initiation up to dying off the above-ground part lasts 26 and 14 months, respectively. Terms of the beginning of phenological phases and their duration are connected with weather conditions of individual habitats: fluctuations of air temperature, amount of precipitation and nature of their distribution, height of snow cover and time of its melting.