Leaf number of Clivia miniata Regel increased significantly with higher temperature (20 degrees C compared with 16 and 7 degrees C). Supplementary lighting (to reach a photoperiod of 16 h) during winter time, had no effect on leaf number but promoted leaf elongation, resulting in poorer plant quality. The first flower bud was initiated after 12-13 leaves were formed, regardless of temperature or light treatment; subsequent flower buds were initiated after each set of four to five leaves. Higher temperatures hastened flower bud development. However, scape elongation was insufficient. Supplementary lighting hastened the latter process.