Growth rates and seasonal development of some varieties of lilac (Syringa L.) in regions with different climatic conditions

Lilac enjoys popularity in landscape design due to its high decorative value during flowering, unpretentiousness, and sustainability. However, depending on the climatic conditions of cultivation, lilacs may exhibit growth and phenological development peculiarities. This work aims to determine the patterns of seasonal development and growth rates of some varieties of common lilac in botanical gardens of three regions: the Republic of Bashkortostan, Perm Territory, and Saratov Region. The work was carried out over three years (2020–2022) based on lilac collections in the botanical gardens of Ufa, Perm, and Saratov. The objects of research are five varieties cultivated in all three botanical gardens (Beauty of Moscow, Salavat Yulaev, Mme Lemoine, Sensation, Katherine Havemeyer), as well as two varieties (Nafisa and Gulnazira) common to the botanical gardens of Ufa and Perm. It has been established that the initial phases of the growing season (bud dehiscence and the beginning of growth of vegetative shoots) in the seven studied varieties of common lilac in Perm, Ufa, and Saratov begin relatively uniformly in each region and generally depend on the average air temperature and the amount of precipitation. The importance of the genetic characteristics of the variety prevails starting from the flowering phase, which is confirmed by the close dates of the beginning of the flowering stages, the end of flowering, and the growth of vegetative shoots, regardless of the place of study. The annual growth of vegetative shoots probably has a more complex relationship, determined not only by specific weather conditions but also by a range of other factors, particularly soil conditions, microclimate, techniques used, and the level of agricultural technology for cultivating samples.