Inadequate light is often a major problem in growing foliage plants indoors. The importance of light cannot be overemphasized, according to Dr. Charles A. Conover, director, University of Florida Agricultural Research Center, Apopka. Many of the foliage plants sold throughout the United States are grown at Apopka, and Conover's main concern is that the plants be healthy and survive as long as possible.
Without ample light, photosynthetic (production of food) processes are inadequate, and death occurs when the supply of stored food is exhausted.
To survive, the plants must be able to tolerate rather dim light for long periods of time or supplemental lighting must be provided.
Foliage plants that may survive up to 12 months with low light of 50 to 100 foot-candles (locations more than eight feet from windows, no direct light, dull hallways) include: commutatum plant (Aglaonema commutatum), pewter plant (Aglaonema roebelinii), Chinese evergreen (Aglaonema simplex), cast-iron plant (Aspidistra elatior), bamboo plant (Chamaedorea erumpens), parlor palm (Collinia elegans), jade plant (Crassula argentia), English ivy (Hedera helix), snake plant (Sansevieria zeylanica) and birdsnest plant (Sanevieria trifasciata 'Hahnii').
Where natural light levels are not adequate, they can be supplemented with artifical light sources.
Light duration is also important, since the total number of foot-candles received during a 24-hour period is a product of intenstiy and duration.
The longer the plant is lighted, the more food produced, and therefore when plants are grown in low light areas they should be lighted for longer periods to counteract low light intensity, Conover says.
Light quality refers to the wave-length of light being received by the plant. Natural sunlight contains all visible wavelengths utilized by plants and is the best and cheapest source of light. Plants may be grown solely under artificial light, however, if the proper quality is provided.
Research has established that plants use chiefly two wavelengths of light, red and blue, to produce normal plant responses. This is important when considering artificial lighting, because fluorescent fixtures provide light predominantly in the blue wavelength while incandescent lights provide light primarily in the red wavelength.
"Supplemental lighting may be applied anytime during the day or night when convenient, or as a byproduct of normal interior lighting.