Experiments are described which indicate that Chrysanthemum cuttings derived from unvernalized long-day stock plants flower sooner and with lower leaf numbers after vernalization than similarly treated cuttings from short-day stock. Long-day treatment of young cuttings also hastens inflorescence initiation provided the period of such treatment is limited and given before or immediately after vernalization. The effect of long day appears to be maximal when vernalization is complete. Long-day treatment cannot substitute for vernalization.