Seasonal development of Philadelphus cultivars in the Mari El Republic

Abstract

Species of the genus Philadelphus L. (mock orange) are among the most popular ornamental shrubs. They are valued for low maintenance, abundant flowering, exceptional aroma of flowers and a prolonged flowering period during high summer, by when many shrubs already fade. The results of phenological observations of 2018-2020 are presented in the article. The objects of the research were the plants of 8 cultivars of mock orange selected by N. K. Vekhov in the Botanical Garden-Institute of VSUT (Yoshkar-Ola, Mari El Republic). The vegetation of plants lasts from the beginning of May to the end of September and has a duration of 177-189 days.  The 'Airborne force' (Vozdushny desant) cultivar was characterized by the longest growing season.  The full leafing occurred in the first decade of June, the growth of scions ended in the first half of August. Flowering began in the third decade of June and lasted on average for 13-28 days. The cultivar 'Vosdushny Desant' has the earliest beginning of flowering, 'Arktika' has the latest one. The plants of 'Elbrus' were characterized by the longest flowering, 'Yunnat' – by the shortest one. There was no connection between the duration of flowering and the structure of flowers.