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Why Is My Cactus Turning White? (4 Possible Causes)

Why Is My Cactus Turning White? (4 Possible Causes)

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Growing a cactus in your garden is a fantastic idea. Cacti are notoriously resilient, and you might have heard that it is one of the only plants that is capable of surviving with ease in deserts as well.

However, there is a considerable difference in growing a cactus in your garden and one that is grown in the deserts.

There are a number of different things that you need to do to properly care for the cactus, and it’s important that you observe the plant on a regular basis to ensure that it is doing just fine.

There are a number of problems that might occur over the passage of time, and it’s important that you fix these issues as quickly as possible.

The cactus is one of the most popular succulents that is easy to maintain and will give busy homeowners the perfect opportunity to enter the world of gardening and plant care.

If you want to start raising houseplants on your own and want to start with something that is easy to care for, you simply can’t go wrong with the cactus.

These are low-maintenance plants that don’t require a lot of attention. But, you should know that this doesn’t mean that you can completely ignore the plant and expect it to thrive on its own.

One of the problems that you are going to notice with your cactus is when the plant begins to turn white over the passage of time. There are a number of reasons why the plant might begin to turn white, and it’s important that you figure out exactly why that is happening before you can decide to fix the problem.

Here are some of the major reasons why a cactus might begin to turn white.

1 – Sunburn

A Prickly Pear Cactus In The Sun

When you plant a cactus outside, especially one like the barrel cactus, you should know that it is going to develop a considerable amount of tolerance to the sun on its south side.

If you transplant this cactus without taking care of the original orientation where it was planted, there is a pretty strong chance that the skin will burn.

The most obvious symptom that your plant is falling prey to sunburn is when the skin begins to bleach out and turn to a shade of white or light yellow. This might come as a surprise to most people, especially those who are under the impression that cacti can easily survive in harsh climates.

While that is true, you also need to understand that the plant takes a long while to build tolerance to the harsh climate.

In extreme situations, the plant might succumb to tissue death and you will notice hardened areas of the cactus dying first. If you are going to move the plant, especially a barrel cactus, you should mark the south side of the cactus first so that you know how to orient it when replanting the cactus.

You should know that sunburn is also likely to occur on indoor plants as well when you move them. So, for instance, if the plant is not used to such strong sunlight and you move it right near the window where it will get sunlight all day long, it is probably going to start turning white after a while.

2 – Mealybug Infestation

A Cactus With A Mealybug Infestation

Mealybugs are harmful pests that can cause extensive damage to your plants if they are allowed to run unchecked. These bugs also leave a white residue on the plants, and can mostly be found on the underside of the leaves.

However, the cacti does not have conventional leaves, so you might see the plant turning white from all around.

A mealybug infestation isn’t hard to deal with; conventional pesticides and high-quality insecticides are able to deal with the problem. But, the problem is to figure out the infestation.

Most people tend to mistake these white patches for mold growth, and don’t realize that the plant might have fallen prey to an infestation.

These white spots have a wispy texture that is very similar to cotton. In certain rare situations, these blemishes might appear due to a fungal infection, but that is usually not the case. You need to use a conventional gardening tool to scrape the white substance off the plant.

Mostly, you will find mealybugs around or underneath this substance. When squished, these mealybugs produce a red juice. Be careful that you do not put too much pressure on the plant itself.

Thankfully, getting rid of this problem won’t be an issue. You just need to use a bit of rubbing alcohol to get rid of the mealybugs from your plant. You can even use homemade insecticides to get rid of the mealybug infestation from your cacti as well.

3 – Freeze Damage

A Catus Turning White From Exposure To Freezing Temperatures

You should know that the plant also turns white when it succumbs to freeze damage. If you left your cactus outside during the frost, it could cause the plant to turn white.

Depending on the amount of time for which the plant was left out in the cold and the fall in the temperature, the chances of survival are likely to vary.

It’s important that you bring your cactus inside during the winter season so that the plant does not fall prey to frost. If you want, you can also cover the plant with a few frost blankets as well.

It’s a great way to care for the plant and prevent it from sustaining excess damage.

4 – Other Kinds of Damage

If someone presses against the cactus or if there is a hailstorm, there is a pretty big chance that the plant is likely to sustain hefty amounts of damage.

The parts that are injured are going to turn white, so you have to make sure that you remove the damaged tissue and let the plant heal itself.

These are just a few things that you should know about caring for the cactus and making sure that the plant does not succumb to serious injuries or problems.

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Thursday 13th of May 2021

Hi, Lisa - I hope this webpage works out for you! Thank you for sharing - I am pretty certain that I sunburned my Christmas cactus, and I think your article confirms that! Maybe it can be salvaged - I hope. It came from cuttings off my grandmother's plant which she got almost 100 years ago, and mine was one of the last in the family. I probably should have started some new cuttings last year.


Wednesday 19th of May 2021

Thank you Edward!

Wow, that is definitely one worth trying to save! What a great history. I would try moving it to a shady area where it only gets indirect light. Hopefully with some shade and care it will be able to recover. Good luck!