What is Etiolation?
Etiolation in plants is a natural phenomenon and is simply a plant’s way of reaching for a light source. If you have ever started seeds without sufficient lighting, then you have seen how the seedlings grow rather spindly with a long, abnormally thin, pale stem. This is an example of etiolation in plants. We generally know it as plant legginess. Etiolation is the result of hormones called auxins. Auxins are transported from the actively growing tip of the plant downwards, resulting in the suppression of lateral buds. They stimulate proton pumps in the cell wall which, in turn, increases the acidity of the wall and triggers expansin, an enzyme that weakens the cell wall. While etiolation increases the chances that a plant will reach the light, it results in less than desirable symptoms. Etiolation plant problems such as abnormal lengthening of stems and leaves, weakened cell walls, elongated internodes with fewer leaves, and chlorosis may all occur.
How to Stop Etiolation
Etiolation happens because the plant is desperately searching for a light source, so to stop etiolation, give the plant more light. While some plants need more than others, nearly all plants need sunlight. Sometimes, no action is needed and the plant will reach the light source undamaged. This is especially true of plants that are under leaf litter or in the shade of other plants. They may naturally grow tall enough to go through the physiological and biochemical changes that occur when the plant has sufficient light after a period of insufficient light. Of course, if you are concerned about leggy plants in the garden, clear out any leaf detritus that is covering the plant and/or prune back competing plants to allow for more sun penetration. This natural process is called de-etiolation and is the natural transition of underground seedling growth to above-ground growth. De-etiolation is the plant’s response to adequate light, thus photosynthesis is achieved and results in several changes in the plant, most notably greening up.
