Why is My Moon Cactus Turning Yellow: 12 Reasons

Why is My Moon Cactus Turning Yellow

Have you ever noticed your moon cactus turning yellow? You’re taking great care of it, but one day you notice it has taken on a yellow tint. Chances are that something has gone wrong in its environment and this is why it’s turned yellow. It could be any number of things from how much light the plant receives through to how often it is watered. Let’s go over some of the common reasons why moon cacti turn yellow with tips on how to help prevent them from happening again down the line!

We will be analyzing all of these factors so that you discover and get down to work to repair your yellowish cacti.

Too Much Light 

Moon cacti do not appreciate too much light as they are already sensitive to bright spots and for this reason, if placed in direct sun, the moon cactus will burn. When exposed to these levels of light, the top of the moon cactus begins to turn a yellowish color.

Although moon cacti are native to desert climates and we know that they’re accustomed to direct sun exposure, one of the things we want you to be aware of is that some types of moon cacti respond poorly if exposed to direct sunlight over a long period time due to a lack of protective pigments. That’s why yellowing may be occurring in some areas of your specimen.

If you have your moon cactus in an area with direct sunlight, it may soon begin turning color of yellow, orange, or white spots. This is especially true if your moon cactus is still young, as older specimens of the plant tend to be more resistant.

For small plants, we recommend you put them in an area that receives the morning sun; once they grow they will be able to withstand better and can be left for more hours.

The right way to take care of cacti is to first accustom them to the daylight. Share your awakening sun with them in your garden, by first being outside for a few short hours and then gradually increasing it until they can be outside for about 5-6 hours each day.

Low Light

The moon cactus is a cactus that requires light to survive. When left indoors without proper lighting, the moon cactus tends to stretch out as it reaches instead for light. This can weaken the epidermis of the cactus, causing it to turn yellow or even white. Its chlorophyll pigments will also begin to deplete which can lead to other problems in this fully developed plant.

Over Watering

Over Watering

Watering your cactus plants too often can be a problem. If you keep the soil wet and do not let it air-dry, it may wilt and become stressed out. This is especially true of moon cacti which thrive best in warm, arid climates.

It’s important not to overfeed your cacti because they will not tolerate being kept in humid environments. An easy way to tell if you’re overwatering is the presence of a yellow hue on the top of your plants. This can be caused by chemical reactions happening slowly at the root level and these reactions cause oxygen tension to decrease.

If you feel like you’ve poured enough water but nothing is getting through the holes in the bottom of the pot, remove any stones stuck to the bottom.

Because they are not exposed to direct sunlight, container gardens do not require as much watering as outdoor gardens.

Excess watering can cause yellow spots on Moon Cacti. The excess water saturates the roots and suffocates them, which causes the fleshy body to become moldy, killing the plant.

If your moon cactus is suffering from rot or yellowing leaves, it might be because the roots have outgrown their container or the drainage isn’t good. The best thing to do would be to plant your cactus in a new pot with a porous substrate that drains well and cover it with a layer of gravel.

If when you touch the yellow part, your moon cactus still feels firm, just stop watering it as often and check that any excess water is able to drain well away from the roots. Little by little, you should notice an improvement. Or if you’re having problems with poor drainage, try increasing your soil’s nonorganic matter.

Lack of Water

Not providing enough water can cause problems for your moon cactus. If you don’t give your plant any water, it will turn yellow and dry out. It’s important to provide adequate hydration throughout the month because this is what keeps your plant healthy and strong.

Plants that have been dehydrated have yellow leaves. To tell if a moon cactus is dehydrated, place your finger onto the yellowed part of the flower to see if it is dry or wrinkled.

The solution to rehydrated moon cactus is more straightforward than reviving a rotten one, so all you need to do is water it until the water comes out of the drainage holes in its pot. But just don’t water too much at once or the plant roots could get overwhelmed.

It is not necessary to water the moon cactus more often than one or two times a month. It takes time for this plant to recover, so you will notice the soil becoming dry enough between watering for you to irrigate again.

The Water Used

It may be possible that the tap water you are using is causing damage to your moon cactus. Inspect your plant’s topsoil. If visible, there should be no yellow spots. The salt that comes with tap water can build up inside of your plant, making it extremely difficult for it to thrive as it needs. If you have seen evidence of this in your moon cactus, use distilled water instead!

Environmental Shock

If your moon cactus was just delivered to you, or if you recently bought one and soon after discovered that its leaves were developing a wrinkled, yellowish tint with some age-looking spots on them, it could be due to an environmental change somewhere in your home, like in a room that’s too hot and dry.


Sticking a cactus on your window can cause yellow discoloration. Windows, especially if they face south, can cast too much direct light on the cactus. Put a sheer curtain over the window. Monitor the cactus for discoloration.

You can also move the moon cactus further away from the window if it seems stressed. It’s important to remember that there are many different species of cacti, so while one might do well inside, another species may need more sun.

Very Small Pot

When you grow a moon cactus, baby cacti will often sprout from the ground. Since yellowing leaves are typically a symbol of stress in succulents, the problem could be that the pot is too small for its height.

Get a bigger pot and move the main cactus into it. Also, invest in the right soil. Keep your baby cacti in a separate pot from the mother because some are more resilient than others and less likely to get damaged or die off with such separation.

Mineral Deficiency

When the minerals in your soil are not enough, the color of your moon cactus will start to show it. Although moon cacti are very hardy plants, they do need the right soil to thrive.


During the winter months, you should always make sure to limit your cacti exposure to cold air. One of the worst things you can do to a moon cactus is exposing it to cold temperatures for too long straight and also keeping it damp frequently as this can cause root rot.


Another possible reason is the infestation of pests.  Moon Cacti are more susceptible to disease when they’re weak, so it may be worth it to invest in a stronger medication if you notice signs of a sickly-looking cactus that may have been attacked by pests. You know perfectly well the sorts of pests I’ve been referring to – little red bugs that look like miniature spiders. Spider mite infestation may be deadly for your plant if left alone or not treated immediately!

Treat immediately by spraying with isopropyl alcohol ( For sale here). Separate the pest-infested plant or it can spread quickly. Be sure to keep the plant out of direct sunlight after alcohol sterilization to prevent sun damage.

Other common pests include mealybugs or aphids. Look for white fuzz on your plants since it is a sure sign you are suffering from mealybug infestations. They feed on delicate parts of your plant and can cause destruction. To remove these pests, wash your plant with the help of rubbing alcohol.

“Our cactus can turn yellow from diseases. The best known is the fungus, which is usually formed by excess moisture. “

Lack of Fertilizer

Fertilizer helps to preserve and maintain the longevity of your cactus plants. These plants tend to require more nutrients than other types of flora in order to thrive, so it is important to regularly supply them with fertilizer. These tiny elements are essential for the preservation of the plant’s elasticity, color, and durability.

Lack of nutrients in the soil, that is, it is poor drainage, often causes discoloration in this type of cactus especially when we do not fertilize it regularly as well as having a lack of macronutrients. If a person does not provide their plant with proper nutrition then it will turn yellow.

Anwar Hossain

My name is Anwar Hossain. I am a cactus lover, researcher, and cactus blogger.

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