During their life cycle, potato plants develop tuberous organs from underground stems called stolons, which allow the rapid development of daughter plants from sprouts at the beginning of the new growing season. The formation and growth of a potato tuber is a complex process that can be divided into separate physiological events. In recent years, several scientific breakthroughs in the signalling pathway of tuberization have revealed novel tuber identity genes and regulatory pathways. Different signalling pathways leading to tuber initiation either act independently or intersect, but all seem to be, at least in part, under the control of the circadian clock associated with phase transitions during the plant life cycle. This chapter integrates the different signalling pathways underlying the process of potato tuber initiation and subsequent tuber growth in relation to timing, tuber physiology, gene expression, and the hormonal changes impacting these processes.