Why Is My Cactus Turning Purple? [5 Reasons Explained]

Cactus is a great plant to grow indoors. And it’s a pretty common houseplant too. Mostly because it doesn’t need much care. However, sometimes this plant can turn purple. 

So, what’s the answer to your question- why is my cactus turning purple

Firstly, this situation can appear because of too much light and temperature. Then you’ll see the plant getting purple due to nutrient deficiency. Overwatering can be another big reason. Also, overgrown or crowded roots can help this situation to take place. Lastly, purple cactus can be an indication of cactus cyst infection. 

Now, these are just the reasons. You need to know how to treat the plant as well. That’s why we’ve not only broken down the steps but also the solutions. 

Therefore, to help the poor plant, please keep reading!

5 Reasons Why Your Cactus Turning Purple

Yup, the causes behind the purple cactus are pretty intense. But sometimes the purple spots can be just fruits. 

Because the prickly pear cactus actually gets purple spots because of its fruits. So yeah if you’ve got this cactus, you can relax!

However, if those aren’t fruits- 

You’ll also notice symptoms like stunted growth, wilting, or even soggy foliage. That’s when you should be concerned. 

So, we’ve discussed the common causes and their solutions-

Excess Light & Temperature

excess light & temperature

Cactus can thrive in bright sunlight. However, indoor cacti aren’t that well known with direct sunlight.

Indoor cactus plants do best under indirect light. At a temperature of 65-90 degrees Fahrenheit in summer. Then at 45-55 degrees Fahrenheit during winter. 

So, if you put it directly under sunlight or a light source, you’ll throw it off. For example, the roots of the poor plant will overheat. Furthermore, it’ll burn and turn purple eventually.

Solution

Now, if this is the actual issue. 

Move your cactus to a place with indirect light. Also, make sure the temperature is not too cold in that place. 

Try to maintain the range of 65-80 degrees during the summertime. And 45-50 degrees in winter. 

Therefore, we suggest placing the plant 3 feet away from a direct light source. This will help the plant get the right amount of light and temperature. As a result, it’ll get better gradually!

Lack of Nutrients

Now, nutrient deficiency is a common reason behind discolored leaves or plants. For example, phosphorus deficiency causes purple mint leaves

However, in the case of purple cactus- 

Lack of magnesium is mostly responsible. You’ll find your cactus not only purple. But also wilting because of this nutrient deficiency. 

If you’ve got a Christmas cactus-

You can be  90% confident that this is the reason behind it becoming purple. 

But to be fully sure, we suggest doing a soil test. This can be done by you or your nearby soil lab.

Solution

To bring back the right amount, you’ve to add magnesium to the soil. 

But how can you add magnesium? 

Well, you can do it by using a fertilizer that’s rich in magnesium. Now, you’ve to pick the best fertilizer for your cactus. Otherwise, the situation might worsen.

Just follow the instructions and your plant will recover in no time! 

However, if you think you don’t want to spend money- 

You can try making your own magnesium spray. 

For this, you’ll need- 

  • 1 tablespoon of Epsom salts 
  • 2 cups of water 

Mix these two together. Then pour this into a 100-150 ml spray bottle. And spray the leaves of your cactus plant. 

The leaves will surely absorb the magnesium-rich formula. So, no worries at all!

Too Much Water

Overwatering your plants is problematic. Because it can help diseases like root rot to occur. 

And root rot is responsible for not only making your cactus purple. But also causes black peperomia leaves

Now, overwatering results in wet soil. And a cactus doesn’t like this type of soil at all. Because its roots will die if the soil stays soggy for more than 3 days. Hence the plant turns purple due to lack of food and water later on.

Solution

Well, it’s a bit tricky to help your plant in such a case. But don’t worry! It’s not impossible. 

So, first of all, prune the affected leaves and roots. For this, use a pair of sterile scissors. 

After that, start removing the soggy soil. Then prepare yourself to replant the cactus. Place it in another pot with enough holes for draining water. 

During the replacement process- 

Use fresh and new soil. Add cactus potting mix as well. Also, make sure not to water the plant as soon as replanting it. 

Instead, wait for its top of the soil to dry. Touch the soil with your hand to know whether it’s dry or not. 

If it’s not wet anymore, water your plant. Provide enough water for it to get out of the drainage holes.

And that’s all you have to do!

Overcrowded Roots

Now, overcrowded roots are another big problem that causes cactus to be purple. This situation can be named root-bound as well. 

This is basically a result of growing cactus in a small pot. Because as time goes by, your little cactus will grow bigger. 

And it won’t fit in that small pot anymore. So, if you don’t replant it in another bigger pot-

The roots of the cactus will come out of the drainage holes of the pot. This is an indication that the roots have overgrown and crowded. 

Thus, if you don’t react quickly, the plant will start lacking food. It then turns purple from green.

Solution

So, how can you solve this problem?

Well, to be honest, it’s pretty easy. Just grab a bigger pot and start repotting the root-bound cactus

But make sure the pot is only one size larger. Otherwise, too much space can also create problems.

Cactus Cyst

Now, there’s a possibility for your cactus to get infected with a specific pathogen. Only if you don’t look after it properly.

Well, this pathogen is named Cactidera cacti. It has a common name too. And that’s- cactus cyst. 

This infection mostly occurs if you use infected soil when planting the cactus. Once the pathogen has got into your cactus-

The plant will show some common symptoms. 

You’ll notice the leaves of the plant have become reddish-purple. And there are little white spheres on the plant’s roots.

Solution

Unfortunately, cactus cysts don’t have any effective treatment.

So yeah, you can’t save the poor plant. You’ve to discard the infected cactus instead.

However, you can definitely learn from this. Which is taking care of your cactus plant properly.

Use clean, fresh, and sterilized soil to plant cactus from now on. Provide the right amount of water, light, and temperature we’ve mentioned.

Furthermore, repot/replant your cactus every 3 years. 

And that’s all!

FAQs

Question: Why does cactus turn brown? 

Answer: Well, there are some common reasons why a cactus turns brown. Firstly, overwatering can be blamed. Because soggy soil causes the root to rot. Therefore, the plant slowly turns brown. Then fungal diseases and insects are two big reasons behind this too. 

Question: Is cactus turning red a concern? 

Answer: To be honest, this red pigment is called carotenoids. The red color appears when the cactus tries to cope with extreme heat. Gardeners named this situation good stress. Because this color makes the cactus more attractive. Thus, it’s not a serious problem. However, you’ve to replace the plant from that spot. Otherwise, the plant can turn purple afterward. 

Question: Why is my cactus turning black? 

Answer: Cactus turns black because of some specific fungal diseases. These diseases can be bacterial necrosis, phyllosticta pad spotting, and crown rot. Cactus can become black due to root rot disease too. 

Question: How to treat purple cactus? 

Answer: Well, the treatment depends on the reason why it has turned purple. For example, you’ve to replant your cactus if the reason is overwatering. And change location to treat sunburned cactus. However, some reasons don’t have solutions such as a cactus cyst. 

Question: Why is my cactus turning pink? 

Answer: Pink color on your cactus can take place due to mainly extreme heat. But this can also happen because of incorrect temperature and over or underwatering. However, sometimes you’ll see pink buds on a cactus. Nonetheless, it’s not that serious of an issue.

Wrapping Up

Now, these are the possible answers to your question- why is my cactus turning purple. Hopefully, you’ve understood where you went wrong. Also, repotting a cactus monthly can cause it to turn purple. 

So, what was the reason in your case? 

Share your thoughts and answers with us in the comment section. Lastly, good luck treating your cactus.

We will be happy to hear your thoughts

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