Introduction. Common horse chestnut (Aesculus hippocastanum L.), an introduced plant, is widely used for landscaping and medicinal purposes in the Russian Federation. Horse chestnuts are most productive in southern regions, and their seeds are used to treat venous disease in official medicine. The flowers of this plant have strong antioxidant properties, but their industrial cultivation in Russia is limited due to harsh climatic conditions, parasites and diseases of the plant, as well as dependence on foreign imports.

Aim. The purpose of the study is to study the rational exploitation of horse chestnuts in order to obtain high-quality materials for use in cultural plantations.

Materials and methods. The subject of the investigation was the horse chestnut flower, which was collected during the dry weather months of May and June 2023 in the Voronezh Region. The raw material was collected at different stages of flowering. The flavonoid content was determined by a previously developed and validated method of quantitative analysis based on differential spectroscopy techniques. Optical measurements were taken using an SF-2000 Spectrophotometer manufactured by the Spectr Design Bureau in St. Petersburg. Extractives, shelf life, and stability were assessed according to the 15th edition of the Russian State Pharmacopeia.

Results and discussion. It has been found that it is advisable to harvest horse chestnuts during the flowering period in late May, when the weather is dry. When harvesting flowers from cultivated plants, it is important to leave some of the inflorescence to ensure natural reproduction of seeds. Other parts that have fallen into the harvested flowers, as well as raw materials that are affected by insects or disease, should be removed. The drying process should be carried out using the air-shade or dryer method at a temperature between 40 and 45 degrees Celsius. Optimal conditions for storage include shelves in a cool, dry, and well-ventilated area, away from direct sunlight. The temperature should not exceed 25 degrees Celsius and the relative humidity should be less than 65 percent. The target group of flavonoids in horse chestnut flower samples collected in the Central Black Earth region (Voronezh Oblast as an example) was (3.51 ± 0.11) %, which meets the previously proposed quality criteria of at least 2 % for raw materials.

Conclusion. Based on the results of the research, instructions for the collection and drying of horse chestnut blossoms have been developed and applied in the scientific and industrial activities of the VSU Botanical Garden, named after Professor Boris M. Kozo-Polyanskiy.