Growth analysis indicates that the plastochron index (PI) is consistently applicable for describing the morphological status of the vegetative tomato shoot in quantitative terms, and pronounced seasonal variability in the growth habit is minimized. However, the PI is not applicable to tomato shoots after flower buds are produced at the vegetative apex. True leaf no. 3 goes through four growth stages which can be characterized in terms of the leaf plastochron index (LPI3). A basipetal trend in leaf growth and development is evident.