GibberelUns (GAs) were effective in promoting flowering in sexually mature (45-year-old scions) grafts of loblolly pine (Pinus taeda L.). Seed-cone production was increased 12-fold in fieldgrown, grafted ramets by bi-weekly, May-September applications of 500 ^g per branch of GA^,,. Gibberellin A3 was equally effective at 500 fig but not at 100 fig per branch, while GA5 was ineffective at either concentration. A second study using potted, less-sexually mature (8-to 10-year-old scions) grafts gave a reduced level of seed cones in response to GAs. However, even on these younger grafts GA4/7 was a significant promotive treatment, GA3 being considerably less effective. Branch girdling, tested as an adjunct treatment, was ineffective. It is now apparent that exogenous applications of GA4/7 are effective on a number of Pinaceae species, and their use to promote earlier and more abundant flowering in breeding orchards of grafted ramets for at least two species, loblolly pine and Douglas fir [Pseudotsuga menziesii (Mirb.) Franco] is practical.