Promising herbaceous perennial plants of the genus <i>Thymus</i> for landscaping in the conditions of the steppe zone of the Southern Urals

Abstract

The article presents the results of the assessment of the decorative effect of perennial herbaceous plants (on the example of the genus Thymus of the Lamiaceae family) of the genetic collection of ornamental crops of the Orenburg branch of the Federal Horticulture Research Center for Breeding, Agrotechnology and Nursery. The purpose of the work is to evaluate valuable decorative features of collectible species specimens of the genus Thymus in connection with the prospects of cultivation in the conditions of the steppe zone of the Southern Urals. The assessment of the aesthetic qualities of 3 species (Thýmus serpýllum, Thýmus marschallianus, Thýmus mugodzharicus) was carried out in 2019–2021 in typical soil and climatic conditions of Orenburg. The phenological phases of the development of collection samples were studied. The assessment of decorativeness was carried out on the basis of a scale developed by Ostapko V.M., Kunets N.Yu. The duration of flowering of groundcover perennials of the genus Thymus in the conditions of the steppe zone of the Southern Urals averaged from 17 to 29 days. Generative shoots of representatives of the genus Thymus are not susceptible to lodging under adverse weather conditions. In the studied perennials, the leaf apparatus is characterized by durability, all leaf formations are present, they are resistant to burnout in the growing zone. Simultaneous flowering of more than 70 % of flowers is inherent in the species Thýmus serpýllum, Thýmus mugodzharic. In the representatives of the genus Thymus in the conditions of the steppe zone of the Southern Urals, the appearance of the second wave of flowering during the growing season was noted during observations. In the observed collection species, the color of the flowers is stable, practically not subject to burnout; the flowers are characterized by low shedding (up to 20 %). The fruits of the studied samples practically do not affect the decorative effect, are not subject to intensive shedding. The results of the decorative assessment (Thymus serpýllum – 170 points, Thymus marschallianus – 160 points, Thymus mugodzharicus – 159 points) indicate the presence of valuable aesthetic qualities in the studied samples, These herbaceous perennials are classified as promising in the conditions of the steppe zone of the Southern Urals. Further study of the representatives of the genus Thymus will clarify the directions of application in landscaping of various scales.