Available light is probably the single most important element contributing to a plants survival indoors.

The indoor environment is relatively constant and pre-determined with respect to temperature and humidity, so light is usually the critical factor. The key to success is to select the right plant for the right place in the first instance relating to available light durations and intensities.

Incorrect selection can create a number of future problems and incur unnecessary costs to put things right. On the other hand, an appropriate selection will bear dividends, simplifying maintenance and reducing long term costs.

Many of the plants used for indoor landscape, come from tropical and semi-tropical regions where some of the above environmental fluctuations are less extreme, making them more suitable subjects for adaptation to the indoor environment.

Even within the natural habitat of these plants, there are those that thrive under different conditions, some will flourish in strong sunlight some will prefer shade; some will enjoy frequent rain, others less so etc. Likewise, in the interior setting, different plant will benefit from different environmental characteristics. The proposed setting will dictate to a large degree which type of plant should be selected.

Light

Light levels in buildings can vary enormously; an atrium may be suffused with light during the day, whereas a conference room may be dark most of the time. Between these two extremes buildings will inevitably have a wide variation of available light, depending on the function of the space.

Light … measurement

Assessing light levels is best done with a light meter (these give readings in Lux or PAR {Photosynthetically Active Radiation}). Many people will rely on experience and try to make a judgment based on their own visual perception, but this can be misleading as eyes very quickly adjust to different degrees of lighting. When measuring the light level, an allowance should be made for the type of light source (natural / artificial), its likely duration, and if ‘natural’ the position of the sun at the time of taking the reading. It is not only the strength of the light, but the duration that will affect the plants performance. (Duration is likely to be more important in relatively dim - artificially lit scenarios).