The time at which plants are transferred to floral-inductive conditions affects the onset of flowering and plant morphology, due to juvenility. Cave et al. show that Australian ephemeral species Brunonia australis and Calandrinia sp. are vernalization-sensitive as very young seedlings, whereas daylength sensitivity in B. australis occurs later after a period of vegetative growth. Extending the juvenile phase favourably increases flower and foliage development in these potential floriculture species.