Seasonal rhythms of development of some species of Spiraea L. and varieties of Spiraea japonica L. f. under conditions of collections the Educational Centre “Botanical Garden” of Saratov State University

Abstract

The article presents the results of the study of phenorhythms and introduction evaluation of five species of Spiraea (Spiraea salicifolia L., Spiraea densiflora Nutt. ex Rydb., Spiraea decumbens W. D. J. Koch., Spiraea chamaedryfolia L., Spiraea japonica L.) and 7 varieties of Spiraea japonica (‘Little Princess’, ‘Anthony Waterer, ‘Golden Princess, ‘Gold-flame, ‘Macrophylla, ‘Crispa, ‘Genpei (Shirobana)’. During phenological observations in the period from 2019 to 2021 at the EC “Botanical Garden” of Saratov State University established the calendar dates of the main phases of development, determined the average timing and duration of flowering in the studied samples. Spiraea japonica varieties have been successfully growing for a number of observed years, retaining their varietal characteristics. Evaluation of the success of the introduction showed that the studied species and varieties of Spiraea japonica turned out to be promising for introduction into culture and can be recommended for landscaping in the conditions of Saratov.