SummaryA clone of dwarf alstroemeria cv. Rosalina propagated in vitro was used in experiments to develop a method for pot alstroemeria production. The aim of this study was to optimize the in vitro rooting conditions of the rhizomes so as to obtain early flowering after transplanting to a greenhouse. The effects of cooling in darkness or in light, the addition of paclobutrazol to the rooting medium and the effect of stage of rhizome development on subsequent flowering were studied. The in vitro rhizome cultures maintained on the rooting medium were cooled at 10°C for 2–5 weeks and at 5°C for five weeks in darkness or under a 16 h photoperiod. To allow root formation and growth, the rhizomes were kept for 10 d at 20°C and 16 h photoperiod before cooling at 5°C and 10°C. Pretreatment with 20°C for 10 d and 16 h photoperiod applied during cooling resulted in superior rooting in vitro and better plant survival in the greenhouse. The faster flowering and most plants flowering were obtained after five weeks of cooling at 10°C under a 16 h photoperiod using pre-rooted rhizomes. Paclobutrazol markedly decreased flower stem length.