Kalanchoe cultivars fall into response groups that range from nine to 13 weeks from the beginning of short days to flower. However, unlike pot mums, Kalanchoes are not as easily programmed. Within a given response group, flowering is often longer in the winter than in the summer. It is, therefore, important for a grower to keep records of response times for specific cultivars under different environmental conditions. Plant age can also have an impact on flowering time.
Older plants tend to flower faster than younger plants.
Temperatures below 62 F or above 75 F during the dark period will delay flowering. Curiously, Kalanchoes are more sensitive to high night temperatures early in the dark period rather than later. Height Control Kalanchoe cultivar vary in vigor. Some may grow tall and faster than others in the vegetative state while some may show more flower stalk elongation than others in the reproductive state. Therefore, cultivar selection is one way to control plant height.