The results of studying the biological peculiari of different varieties of the flowering shrub Hibiscus syriacus L. are discussed in the article. An analysis of the phenological development stages of varieties has been carried out. Varieties are distributed according to the time of budding for early vegetation beginnings (from the II-III decades of March) ‘William R. Smith’, ‘Hamabo’, ‘Blue Bird’, ‘Rubis’, ‘Dorothy Crane’, ‘Pink Giant’, ‘Woodbridge’; medium-growing vegetation (from the III decade of March — I decade of April) ‘Matilda’, ‘Roseus Plenus’, ‘Carneus Plenus’ and lategrowing vegetation (from the II — III decade of March) ‘Roseus Plenus’, ‘Lady Stanley’, ‘Speciosus’, ‘Coeruleus Plenus’, ‘Duc de Brabant’, ‘Jeanne d’Arc’. Varieties are ranked by flowering dates for early flowering (from the III decade of June) ‘William R. Smith’, ‘Matilda’, ‘Hamabo’, ‘Blue Bird’, ‘Rubis’, ‘Dorothy Crane’, ‘Pink Giant’ and ‘Woodbridge’; medium-beginning flowering (from the I-II decades of July) ‘Matilda’, ‘Coeruleus Plenus’, ‘Speciosus’, ‘Carneus Plenus’, ‘Lady Stanley’, ‘Roseus Plenus’; late beginners of flowering (from the III decade of July — the I decade of August) ‘Duc de Brabant’, ‘Lady Stanley’.