We studied the growth and bud formation of an evergreen and a deciduous oak species in a Mediterranean area. The phenology of 15 individuals per species was recorded over 4 years and organogenesis in apical buds in two individuals per species over 1 year. Both species showed similar seasonal patterns, although bud opening was later in the evergreen. Summer growth competed with bud formation, and heavy fruit crops reduced bud size and flower number the following year, influencing growth and reproduction.