Solidago x luteus is a hybrid between Solidago ptarmicoides and Solidago canadensis. This hybrid, Solidago chilensis and Aster ericoides cv. 'Montecasino' are the subject of the present work. They are typically long-day plants which grow as rosettes in short days and are exploited as cut flowers. The effect of photoperiod on vegetative development and floral induction of these species was studied. Since the best floral induction performance was observed in Solidago x luteus, studies of photoperiodic behavior of floral bud to anthesis were done with this specie. Floral induction was generally promoted, and the number of lateral branches and leaves increased under long days (20h) in all species. Solidago chilensis plants remained as rosettes, while in Solidago x luteus floral induction occurred under short days (8h). However, Aster ericoides showed both responses, rosettes and floral induction. The hypothesis that short days speeded up flower anthesis in Solidagox luteuswas tested in the experiment with different short days periods (5, 10 and 15 days). Finally, was showed that the rate of flower bud development to anthesis was more rapid in shorter photoperiods (8h, 10h, 12h), delayed in long photoperiods (16h, 20h) and, in photoperiods between 12h and 16h (14h), a transition situation between short and long days, characterizing this response as a quantitative with the increase of photoperiod.