Cut flowers of eight cultivars of Rosa hybrida L. were held in preservative solutions containing up to 4 mg F-/liter. Leaf diffusive resistance was increased by holding flowers in F-solutions. In most cultivars, fresh weight gain was decreased, the degree of flower opening was affected, and visual symptoms of injury were noted in the presence of. F- in the holding solution. Damage at 2 mg F-/liter was almost as severe as at 4 mg/liter. Number of days to petal abscission or bent-neck was shortened by F- for `Samantha' and `Bridal Pink'.