A gravity system was developed for measuring xylem conductivity in excised stem sections from ‘Red American Beauty’ roses. The system was reliable for measurement of the potential xylem conductivity which closely corresponded to actual water uptake in cut roses. Distilled water, sucrose, 8-hydroxy quinoline sulfate (8-HQS), and a modified Cornell solution (2% sucrose + 200 mg/liter 8-HQS) were tested for their effects on xylem conductivity and vascular blockage in excised stem sections. The modified Cornell solution showed the most favorable effects on conductivity, vase life, and appearance. The browning of stem tissue with 8-HQS was associated with a depressed rate of metabolism as measured by a modified triphenyl tetrazolium chloride test. Good xylem conductivity and a low incidence of vascular blockage was associated with the 8-HQS-depressed metabolic rate indicating an active process, attributed to a wound response triggered by excision of the cut flower, in the stem is responsible for vascular blockage. However, microscopic observations of fresh, frozen, and permanent tissue sections of rose xylem showed no evidence of lignin, tannins, or tyloses which are reputed to accompany wound response in plants.