Ornamental shrubs for landscaping in the Northern Region of Kazakhstan

Abstract

Background and Aim. The natural and climatic conditions in Northern Kazakhstan significantly restrict the diversity of indigenous dendrofloral species and the range of suitable ornamental plants for landscaping purposes. The introduction of foreign-selected ornamental shrub varieties is considered an effective approach to expanding the range of resistant ornamental plant species that can withstand the adverse effects of the local environment. The goal of this study is to comprehensively evaluate the ornamental characteristics of introduced species and varieties of ornamental shrub plants in order to identify the best candidates for use in landscaping projects in Northern Kazakhstan settlements.

Materials and Methods. The research was carried out at the plant collections of the KazRIFA (Shchuchinsk, Akmola Region). The study included 23 varieties and species of ornamental bushes belonging to eight different genera (Spiraea L., Physocarpus (Cambess.) Maxim., Dasiphora Raf., Sorbaria (Ser. Ex DC.) A. Braun, Philadelphus L., Forsythia Vahl, Syringa L., Symphoricarpos Dill. Ex Juss.). The ornamental quality was assessed based on morphological and phenological characteristics, as well as cold hardiness and damage resistance.

Novelty. This study provides a comprehensive description and quantitative evaluation of introduced ornamental species and varieties from foreign sources under the harsh continental climate conditions of Northern Kazakstan, considering both aesthetic and adaptability parameters.

Results. A high ornamental rating (32-42 points) has been assigned to 20 varieties, including those from the Physocarpus (Cambess.) Maxim. (41-42 points). A moderate rating (30 points) was given to Spiraea cinerea «Grefsheim», due to occasional reductions in flowering and leaf color intensity. Low ratings (18-20) were assigned to Philadelphus microphyllus A. Gray and Philadelphus grandifloros Wild., due to inadequate reproductive development during the observation period. Most bushes exhibited a balanced crown shape, abundant flowers, vibrant autumn foliage, and resilience to abiotic stress, making them ideal for landscaping applications in northern Kazakhstani regions.