Daylily (Hemerocallis) is a perennial herbaceous plant widely used in landscape gardening. Daylilies are prized for their long term flowering mainly in late summer and low maintenance cultivation. According to flower spike height, the varieties are divided into runt, medium-growing and tall. The article contains the results of the study of 21 medium-growing daylily varieties’ terms of flowering in the botanic garden of the Volga region State University of Technology (Yoshkar-Ola, the Republic of Mari El). The research was conducted in 2015 - 2017. The calendar dates were converted into a continuous series. All varieties were classified as early, medium or late according to the terms of the beginning and the end of flowering and its duration. During three years of research, the earliest beginning of the phenological phase was registered in 2016, and the latest one  - in 2017. The early beginning and ending of flowering were typical for the varieties “Dr Regel” and “Royal Sovereign”. The late beginning of flowering was registered for the “Country Club” variety, and the late ending - for “Sandalwood”. Other varieties were classified as medium-term. The varieties “Royal Sovereign”, “Tejas”, and “Sugar Candy” are characterized by a short flowering period, while “Sandalwood” and “Derby Bound” - with a long one. It was established that the late-flowering varieties are characterized with a longer flowering period.

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.