The effect of exogenous gibberellin (GA3) on shoot apical meristem activity in conifer vegetative buds was investigated by spraying 0 or 0.1% GA3 on the foliage of first-year Scots pine (Pinus sylvestris L.) seedlings twice weekly for 9 weeks during development of the terminal long-shoot bud. Exogenous GA3 promoted mitotic activity in the apical zone, thereby increasing both the rate and duration of cataphyll formation and giving rise to a higher and wider apical meristem. The increase in number of cataphylls increased the number of axillary meristems, which developed as short-shoot buds.