Flower longevity refers to the period during which flowers remain open and functional. Orchids are well known for their relatively long-lived flowers. The scape of inflorescences serves as a bridge between nutrient sources and flowers; however, although it plays essential roles in floral display, the mechanisms underlying the maintenance of flower longevity by the scape in Dendrobium orchids remain poorly understood. In this study, using Dendrobium ‘Garnet Beauty’, we investigated the contribution of the scape to flower longevity, based on metabolomic analysis, characterization of physiological responses, and morphological observations. We found no significant differences in the lifespan or morphological structure of the distal or proximal flowers on the scape. However, primary metabolite contents in the distal portion were significantly higher than those in the proximal portion, and the total areas of vascular bundles and phloem in the distal portion were larger than those in the proximal portion, indicating a higher nutrient transport efficiency in the distal portion. Furthermore, the scape showed increases in the contents of different amino acid derivatives and organic acids with age, indicating a relatively efficient recycling and utilization of nutrients within flowers. These findings indicate that the scape contributes to maintaining consistent flower longevity by enhancing nutrient transport capacity and provides storage capability that ensures the delivery of a steady supply of nutrient to flowers.