The effects of cultivar and planting season on growth development and pod yield of snap bean (Phaseolus vulgaris L.) were analysed in a 2-year, 2-location experiment in Spain. Phenology, pod production, and quality differed significantly among snap bean cultivars. Planting season had a significant effect on most pod traits except the number of seeds per pod, length, thickness, soluble solids content, tenderness, and string, and this effect varied markedly among environments. High and negative correlations for vegetative growth traits between early and late planting seasons confirmed the strong planting season influence on those traits. Fresh pod yields were highest in the early planting season, and the longer pod maturation phase could be considered to be one of the main factors. Planting of snap bean earlier in the season should thus contribute to a longer growing vegetative cycle and greater productivity than normal or summer and late autumn planting. The earliest maturing snap bean cultivars would have the highest fresh pod yields in late planting seasons, while the latest maturing snap bean cultivars would have the highest yields in early and normal planting seasons. These results will allow breeders to optimise the level of earliness for each planting season without reducing the yield. This is a key requirement for snap bean crops, and it is the first step towards selecting parental lines with stability of pod traits to be used in breeding programs for different growing areas and planting seasons.