Abstract: Dahlia Cav. is a beautifully flowering perennial plant from the family Asteraceae Dum. It has storing root tubers that do not survive during the winter in the open ground of central Russia. This crop is characterized by a high variety of colors, shapes and sizes of inflorescences, different plant heights, long-term stable decorative effect from the beginning to the end of the growing season. The purpose of the study is to analyze the Dahlia × cultorum collection in the Botanical Garden-Institute of the Volga State University of Technology (Yoshkar-Ola, Mari El Republic). As of 2021, plants of 32 cultivars were grown in the exposition «Ornamental Herbaceous Plants», each cultivar is represented by 1-5 plants. It is established that the available cultivars belong to 6 classes according to the structure of inflorescences, the largest number of them belong to the class of Decorative and Semi-Cactus (12 and 8 names, respectively). According to the color of the inflorescences, the largest number of cultivars has bicolor inflorescences. The small-flowered cultivars dominated according to the inflorescences size. In general, most cultivars with large and medium-sized inflorescences have a decrease in their size. We can replenish the collection with varieties from the smallest represented classes, as well as the missing 6 classes. The results can be used in the practice of settlements landscaping of the Mari El Republic and nearby regions.

Abstract: Daffodils are decorative spring-flowering bulbous plants characterized by unpretentiousness to growing conditions, abundant flowering and variety of flower shapes. The timing of their flowering depends on varietal characteristics, weather conditions and climatic conditions of the growing point. The purpose of this article was to study the seasonal development of 6 Daffodils varieties in the Mari El Republic. Observations were carried out in the Botanical Garden-Institute of the Volga State University of Technology (Yoshkar-Ola). The objects of the study were varieties: small-cupped– 'Carnmoon' and 'White Lady', large-cupped – 'Duke of Windsor' and 'Odense', double – 'Texas' and 'Yellow Cheerfulness'. Observations were carried out in 2014-2019 according to the methodology of the Main Botanical Garden of the Russian Academy of Sciences. It was found that the varieties starting vegetation later had a longer vegetation period. The dates of the beginning and mass flowering correlated with the dates of complete leaf death. The variety 'Yellow Cheerfulness' had the late passage of all studied phenophases, as well as the shortest duration of vegetation and growth. The variety 'Odense' was characterized by the early end of leaf growth, budding and flowering. The variety 'White Lady' had a long vegetation period and the leaf growth period, a late flowering end and a long flowering duration. The short duration of flowering is established in the variety 'Carnmoon'. The data obtained are of interest in the practice of daffodils growing in the settlements of the Mari El Republic.

Abstract: Crocuses are beautifully flowering corm-bearing plants. They begin the growing season immediately after the snow melts. The research contains the results of phenological observations of 2014-2019 for plants of 6 Crocus taxa in the conditions of the Mari El Republic. Cultivars with early, medium and late periods of phenophase passage were identified. A flowering phenospectrum of the studied crocuses has been compiled. Crocuses vegetate from mid-April to early June for 40-50 days, and bloom from the third decade of April to early May. C. chrysanthus 'Prince Cloues' is characterized by the earliest unfolding of leaves and a short duration of their growth. The greatest value for landscaping is C. versicolor, characterized by the longest growing season and the earliest flowering, as well as C. chrysanthus ' Romance’ and C. angustifolia, characterized by the longest flowering within 2 weeks. The flowering of C. sieberi 'Spring Beauty’ is unstable. The obtained data on the seasonal development of crocuses can be used when including them in rockeries, alpine slides and other flower beds in natural-style gardens.