Objectives Rose (Rosa hybrida L.) is a beautiful and widely cultivated flowering plant around the world whose quality is of great commercial importance. The objective of this study was to investigate the impact of foliar application of calcium nitrate on the quality and postharvest life of two rose varieties (cvs. Samurai, and Jumilia) in a soilless culture system.

Methods The research used a hydroponic culture method, the roses plants were grown in Hoagland nutrient solution containing 50% less Ca for a total span of 4 months. One month was dedicated to plant acclimatization, and 3 months for spray treatment. Two rose varieties (Rosa hybrida L.), cvs. Samurai and Jumilia plants were used as test materials and planted in pots containing 100% perlite (3–5 mm). After one month of culture, 160 mg/kg CaNO₃ solution was sprayed, and each treatment corresponded to the first, second, and third harvests, respectively. The plant and flower growth indicators and flower vase life were investigated after each harvesting immediately.

Results A positive impact of foliar-applied Ca on stem characteristics, pedicel dimensions, corolla size, flower attributes, and vase life was found. Furthermore, a general trend was observed, wherein an increase in the number of harvesting stages led to improved traits. Notably, Jumilia rose consistently exhibited lower values for all studied traits, except for flower vase life, in comparison to the Samurai rose. While there were no significant differences in length values between Samurai and Jumilia roses due to calcium foliar application across the three harvesting stages. Duncan’s grouping revealed a specific effect on Jumilia roses during the third harvest stage. Calcium fertilizer significantly increased photosynthesis rates of of rose leaves in the calcium treatments compared with the control treatment.

Conclusions Foliar spraying of calcium nitrate is an effective measure to promote the growth of roses and improve the yield, quality and bottle life of fresh cut flowers.