This study aimed to estimate plastochron, leaf area, and yield of Physalis peruviana seedlings grown in different environments and transplanted on different dates. The experiment was carried out in a completely randomized design, arranged in a 2 x 3 factorial scheme, namely: two cultivation environments (protected and field) and three transplanting dates (10/27/2013, 12/15/2013, and 02/11/2014). Four replicates of eight plants were used per plot, and the four central plants composed the useful area. Based on mathematical models and temperature data, plastochron was estimated for the entire crop cycle and vegetative and reproductive phases separately. Leaf area and node number were measured, and their relationship established at the end of the study. Other variables assessed were fruit number, mass, and yield per plant. Our results showed that the higher temperatures in the protected environment anticipated phenological timings. Plastochron values of 60.0 and 16.5 °C day-1 can be used during vegetative and reproductive stages, respectively. The protected environment increased vegetative growth and development, as well as yield of P. peruviana seedlings. In the Guarapuava-PR region, P. peruviana seedlings should be transplanted during the spring so that higher fruit yield and quality could be achieved.