Etiolation in cacti is a process by which the plant becomes paler, its stems become unnaturally long and thin, and its growth becomes stunted.
This happens when the plant endures a lack of light for extended periods of time. Its limbs become long and thin because it has become desperate for any available light and is literally growing in the direction of the nearest light source.
A cactus, like any plant, cannot survive without light; it needs it to photosynthesize.
In this article, we will discuss more about cactus etiolation, what you can do to fix the problem, and how to prevent it from happening in future.
What is cactus etiolation?
Etiolation is a plant’s response, or survival strategy, in the absence of sufficient light for prolonged periods of time.
Cacti live in some of the sunniest regions on earth and have adapted to flourish in these conditions. That means that if you are growing a cactus at home, the best light you can give it is the same bright light it would get in the wild.
If the cactus does not get the light that it needs, its growth will be affected.
Etiolation itself is not harmful to the plant, although it can affect the plant’s symmetry and aesthetic. The lack of light, on the other hand, is of great concern in this situation, and will need to be addressed promptly if you want to save your cactus.
Signs of cactus etiolation
An etiolated cactus will not grow as well as one that gets all the light it needs. This is because, without light, it cannot photosynthesize properly, which is how a plant creates food for itself to grow.
The cactus will therefore be shorter and thinner than it should be.
Another sign of etiolation is a loss of color in the plant. This is one of the first signs you might notice in your cactus. Chlorophyll is the green pigment that a plant produces through photosynthesis, and that is what gives plants their green color. The less chlorophyll there is, the less green the plant becomes, becoming more yellow or white instead.
Thinner growth at the top
A healthy cactus tends to have a rounder and thicker upper part. If you see pointy growth at the top of the plant, it could be due to etiolation. The new growth will look something like a pyramid because the plant is trying to grow longer, as fast as possible, using the remaining resources it has. Growing a thick stem will take too much of its energy, which it does not have in its current state.
The cactus is favoring one side
This is another tell-tale sign of etiolation. An etiolated cactus might lean to one side if the closest source of light is in that direction.
This happens even to cacti that do get light but are not rotated regularly. It is always best to place the plant in a spot where all sides can get exposure to the light, so that it grows straight and even.
Abnormal looking spines
An etiolated cactus will also have malformed spines. The spaces between the spines will start to become wider and wider, while each spine becomes shorter and thinner. The spines can even cease to grow altogether.
Low light conditions and etiolation can also affect the cactus’ ability to produce flowers. This is because of the reduced resources and energy caused by the lack of light.
A cactus’ energy and resources become very depleted when it is etiolated, so the plant will concentrate what little stores it still has on survival, which it does by growing long, thin limbs to reach the nearest source of light. Flowers are not its priority in this situation.
Cactus etiolation – Causes
Low light conditions
The majority of cacti require a great deal of light. As a result, if they are grown indoors, their growth is stunted to some extent.
Cacti stretch out in search of better lighting conditions, so when they do not get enough light, they will lose their natural shape and become distorted.
For this reason, before you bring your succulents or cacti indoors, it is critical to understand their lighting requirements and position them where they can receive sufficient light.
Although the amount of light is important, the direction of the light also plays a role, because if there is only light coming from one angle, the cactus will try to orient itself toward that.
For example, they will stretch toward windows or other nearby light sources in order to get more light. Rotating the pot on a regular basis will help to prevent this from happening.
You should rotate the plant every few months if you keep it near a window; you can do this when you water them.
Cactus is unable to go dormant in the winter
Another common reason for etiolation in cacti is if they are not able to go into dormancy over winter. Your cactus will naturally hibernate if you live in a region where winters are long and cold, as is the case in many parts of the world.
If the plant cannot go dormant at the appropriate time, it will continue to grow in an unfavorable environment, and will become etiolated.
To prevent this from happening, you need to observe the plant’s dormancy period, and even force it to hibernate if necessary. To induce hibernation, stop fertilizing over winter, expose the plant to lower temperatures, and reduce your watering significantly.
When temperatures begin to fall in the northern hemisphere, in October and November, you can begin to make these changes that will help your cactus enter its hibernation state.
How to fix an etiolated cactus
When a cactus is etiolated, it is not possible to restore its aesthetic. You can, however, attempt to correct the growing conditions and make it more healthy going forward.
Reduce the amount of water you use
In response to excessive watering, cactus roots will spread outwards to reach the water, and away from nutrients.
If you reduce your watering, you should see a better balance between root growth and nutrient absorption.
Increase the exposure to natural light
This is the most straightforward measure to correct etiolation in cacti. If your cactus has been in low light conditions for a while, you need to expose it gradually to more and more light each day, until it adapts to normal levels of light again. If you keep the plant near a window, make sure to rotate it every couple of weeks so that it grows evenly.
Take the cactus outdoors
In some cases, if a cactus has recently been relocated to an area with limited natural light, it may begin to show signs of etiolation.
In this case, it may be necessary to move the plant to a more suitable location.
If you do not have any outdoor space for it, move it to a sunnier spot or place it in front of a window that lets in lots of sunlight.
Increase the air circulation
It is possible for etiolation to occur due to insufficient air circulation around your plants.
Make sure that the foliage is not cramped against other plants or objects, as this will allow for better circulation around it.
Pruning and trimming
Etiolation can also be caused by damage to the plant’s foliage in certain circumstances.
The most effective way to deal with this is to remove any damaged parts as soon as possible, before they rot or become infected with bacteria. If you want to take preventative measures against future problems, you can use a fungicidal spray.
Trimming etiolated cacti is one of the most straightforward methods of treatment. If there is a section of the cactus that became thin from etiolation but has now started growing normally again, making the top part thicker and heavier, this can cause the thin section to snap or break. You might need to cut that section off at the thin part. Do not worry, though, because you can actually use that cut stem as a cutting to propagate the plant.
How to prevent cactus etiolation
It is possible to avoid etiolation if you take the necessary precautions. The most important point to keep in mind is that cacti are desert plants that require a lot of light.
Try to get the plant outside as much as possible if you live in an area with poor lighting. This will ensure that it receives adequate sunlight for photosynthesis.
Another way to prevent etiolation is to water the plant correctly – neither too much nor too little – while also ensuring that the plant’s skin does not come into contact with too much water.
Last but not least, it is critical to ensure that your cactus receives the nutrients that it requires.
If you feed your cactus properly and provide it with adequate light for photosynthesis, it will grow tall and strong, with healthy spines.
Cactus etiolation is a condition wherein the plant starts growing unnaturally long and thin stems and becomes pale, due to a lack of sunlight.
The plant has been in low light conditions for so long that it has become desperate for light to survive, so it uses all its remaining energy to stretch itself toward the closest source of light.
A cactus can also become etiolated if one side of the plant does not get as much light exposure as the other, or if it is not able to go dormant during the winter.
You can save an etiolated cactus by transferring it to a sunnier spot, giving it a little less water and good air circulation, and pruning it if necessary.
Prevent etiolation by making sure that your plant always gets the light it needs.
Image: istockphoto.com / Eduarda Brodbeck