In the present study, we tried to determine the vase life of cut carnation flowers of the spray type by observing the number of open flowers, i.e., the percentage of open flowers to the total number of initial flower buds. The vase life determined by this
method was similar to that determined by measuring ethylene production and observing senescence symptoms of the carnation flowers. In addition, the present method effectively evaluated the action of preservatives, sucrose and DPSS, for carnation flowers. These findings indicate that the determination of the vase life of the cut carnation flowers of the spray type by observing the number of open flowers is as effective as that by the observation of senescence profiles and ethylene production. Thus, the present method for the determination of vase life can be used as an alternative method for the determination of the vase life of carnation flowers, especially those of the spray type.