The grapevine buds are compound buds each containing three buds. The primary bud contains the most flower clusters, the secondary fewer clusters, and the tertiary bud contains no flower clusters. The three buds are varying in cold hardiness. The primary bud is least cold hardy, the secondary is a bit hardier, and the tertiary is most cold hardy. The picture above is of two of the three buds pushing out of a cane that was buried in the dirt. In regions where the temperature does not damage the buds, the secondary and tertiary buds are normally plucked off early in the growing season to prevent crowding of the fruit zone.