Light
Light is one of the main environmental factors controlling plant growth. For indoor cultivation, it is useful to look beyond simply asking “how bright is it?” and understand how much usable light reaches the plant, for how long.
Intro
Light intensity
Light intensity is how much usable light reaches the plant. It can be measured as PPFD, while lux can be used as a simple reference when a PPFD meter isn't available.
For many aroids, around 100–300 µmol/m²/s PPFD is a practical starting range, depending on the species and growing conditions.
Light spectrum
Light spectrum describes the different wavelengths of light reaching the plant. Plants use different parts of the spectrum for photosynthesis and other processes, so the spectrum can influence how they grow and develop.
For indoor growing, a broad spectrum covering roughly 400–700 nm is a good practical choice for most aroids.
Photoperiod
Photoperiod is how long your plant receives light each day. For example, a 14/10 cycle gives the plant 14 hours of light and 10 hours of darkness.
Many aroids can be grown under long indoor photoperiods, but the ideal cycle depends on the species and the total light intensity.
In our own growing, we currently use 14 hours of light. We have observed increased nectar production on some leaves after changing our growing conditions, but we cannot yet say whether the photoperiod, stronger feeding or another factor caused it.
Observation first. Explanation later.
Light stress
Too little or too much light can stress a plant. Low light can lead to slower growth and weaker development, while excessive light can cause bleaching, yellowing, leaf damage or excessive heat.
The right intensity is therefore not simply “as much light as possible.” It is the amount the plant can actually use under its current conditions.