Dahlia flowers are sensitive to ethylene, but ethylene production by floral organs did not significantly increase during flower senescence. STS did not extend vase life of cut flowers, but 1-MCP extended vase life of florets. When BA was applied either to florets by dipping or to flowers by spraying, the vase life of dahlia was extended. In addition, BA dip treatment extended the vase life of florets more than 1-MCP treatment. Ethylene thus appears to be partly involved in natural senescence of cut dahlia flowers, and direct application of BA to petals by dip or spray is effective in extending their vase life.