Globe artichoke (Cynara cardunculus var. scolymus L.) is an herbaceous, perennial plant native to the Mediterranean region and belongs to the Asteraceae family. It requires adequate winter chilling for bud induction, yet susceptible to freeze damage. In subtropical or tropical climates, artificial flower induction or vernalization is necessary for winter crops. Our preliminary results indicate that gibberellic acid (GA3) effectively induces bud formation without chilling. Understanding crop phenology facilitates management planning and performance assessment under diverse conditions. This study used the Biologische Bundesanstalt, Bundessortenamt, CHemische Industrie (BBCH) scale to characterize the phenological development of artichoke cultivated in a subtropical climate with insufficient winter chilling. Seedlings of ‘Green Queen’ (GQ), ‘Imperial Star’ (IS), ‘Opal’ (OP), ‘20-063’, ‘22-017’, ‘23-057’, and ‘24-060’ cultivars were transplanted on 18 October 2024 in West Central Florida. Plants initially exhibited vegetative growth characterized by leaf development (Stage 1) and rosette formation (Stage 3–4) up to 79 DAP. GA3 applications at 62 and 76 days after planting (DAP) promoted vegetative growth by increasing both leaf number and size. Vegetative growth was most vigorous in ‘GQ’ and least in ‘20-057’, whereas in the Mediterranean climate, growth at this stage typically arrests through winter due to low temperatures. GA3 applications successfully induced bolting, initiating the transition to reproductive growth between 80 and 82 DAP. Buds reached the optimum maturity stage to harvest with the maximum diameter at around 115 DAP, earlier than the typical 120 to 150 days in annual culture. Marketable yields varied significantly among cultivars, from 2.69 t·ha–1 for ‘OP’ to 7.33 t·ha–1 for ’20-063’. By 160 DAP, mature buds exhibited floral opening with characteristic lilac-colored florets (Stage 6: flowering and capitulum formation). In Florida, although hot and humid summers constrain the harvest window, our results suggest that GA3-induced vernalization enables artichoke production during the winter months in a timeframe that is 5 to 35 days shorter than under Mediterranean conditions. This study advances understanding of artichoke adaptability to subtropical climates, promoting its potential as a winter specialty crop for edible and ornamental uses.
