Plants stay vegetative with daylenghts of more than 13 hours. Blackout for flower induction has to be applied continuously every day for the first 7-9 weeks after the start of blackout. After the flower buds are visible, the plants can be exposed to long days, but the quality of most cultivars will improve if blackout is applied until marketing. Kalanchoe require relatively high light levels throughout the cultivation cycle. Dark weather results in slow growth and in poor shoot formation.
Assimilation lighting during winter is very beneficial.
Excessive light levels in summer will cause discoloration of the foliage and fading of the flower colours. Good control during the short day period is essential. The control of relative humidity is important but difficult in Kalanchoe cultivation. As CAM plants, Kalanchoe reduce the evaporation of water during bright days. At the same time it is necessary to ventilate the greenhouses for temperature control.