The article establishes the regularities of growth and development of tree-like willows growing in the city park of the city of Volsk under the influence of various water sources. The research methodology was based on the relevant GOST standards, recommendations of scientific institutions and scientific research. The variance analysis of the annual increments of 12 Salix species allowed us to establish patterns depending on the moisture content of the growing seasons of 2018, 2019 and 2022. It is determined that under natural conditions of humidification, the values of the willow branches’ increments in length depend on weather conditions, the lower the hydrothermal coefficient, the smaller the increments. Pond, stream, ground water available for roots increase the increments of Salix species up to 78.7%. The variance analysis of two-factor experience has established significant differences in both factors and their interaction. Regression and correlation analysis revealed that annual increases by 83% depend on weather conditions and the type of water source. It was revealed that the best tree-like willows growing on the territory of the park of culture and recreation in the city of Volsk are the following species: Salix babylonica var.tortuosa x alba var.recticapus (S. X ‘Sverdlovskaja Isvilistaja 2’ V. Schaburov et I. Beljaeva), Salix schwerinii x dasyclados (S. X ‘Rekord’ V. Schaburov et I. Beljaeva), Salix hybrida “Schater 1”, Salix matsudana Koidz., S. schwerini x (schwerinii x udensis) (S. x ‘Schwerina Ulutschennaja’ V. Schaburov et I. Beljaeva).