Among all the environmental factors, light is usually the most limiting component in the care and the growth of indoor plants. Every species has boundaries which are related to its natural habitat, the intensity of light in which it was cultivated, and the degree of acclimatisation that has been achieved.
Many palm species are considered to be the least demanding among all plants, with regard to the amount of light they need for their care. Even so, palms that have been cultivated in full sun have leaves which differ both structurally and morfologically from those grown in shady places, thus making it hard for the former to photosynthesise to the light intensity found indoors.
When interiors do not have sufficient natural light, we can use supplementary artificial light, it being crucial to know that the spectrum of artificial light complements the other in the right ratio to meet the palm´s needs.
As we can observe in fig. nº1, plants do not have the same sensitivity to light as does the human eye.. Its maximum effectiveness is found on the red (675 nm.), this wavelength being the one that absorbs the highest quantity of CO2 through photosyntesis (CO2 + H2O + Light = Carbohydrates + O2).
There are many kinds of lamps on the market that are good at providing overall illumination, as well as looking after the needs of the plants. Those that give a white light are probably the best, as long as their spectrum gives the maximum in the red and blue (400-700 nm.). There should not, however, be a marked imbalance between those areas, nor should the lamp produce radiation with a high level of infra-red light.
Proximity to the source of illumination is another factor to consider. As light decreases rapidly with distance, we should take the maximum advantage of sunshine by not placing the plants too far from the windows.
