Moon Cactus Losing Color: Yellow, White, Brown, Red, and Black

why Moon cactus losing color

Like other cacti, the moon cacti are painstaking, resistant, and low care plants. But what makes it different is its color. It is gifted for its color like yellow, red, orange, pink, coral, peach, purple, and white. But if such gifted things are being got faded away or got colorless, it must be a heartbreaking event for moon cacti lovers. But isn’t it wise to ask why your moon cactus is losing color? Here is why.

Moon cacti are made of two parts: scion and rootstock. One loves indirect sunlight, and the other like direct sunlight. There are some other reasons for discoloration of your cacti like corking (old age), overwatering, underwatering, insufficient nutrients, root rot, stress, strain, etc.

Unfortunately, your moon cacti don’t lose color in one form. It could be discolored in different hues like yellow, white, brown, red, and black. Let’s explore every discoloration reason and its remedies.

Colors of Moon Cactus

colors of Moon Cactus

There are different types of moon cactus available. Most popular and well-known colorful moon cacti are yellow, red, pink, violet, green, two toned- yellow and orange, pink and violet, violet and red, green and yellow,  tricolor: yellow, green and red.

Why Is Your Moon  Cactus Turning Yellow?

Turning Yellow

Placement: While easy to look after, cacti require a very specific amount of indirect light per day. If moon cacti are being placed on the window under direct sunlight, it will damage its scion and rootstock also. 

Instead, place the cacti behind a thin and transparent curtain, which will filter the direct sunlight. The amount of sunlight would be enough for moon cacti well-being, and the plant won’t burn from the sunrays.

Watering Incorrectly: Though cacti are considered desert plants, they still need the right amount of water. Besides, make sure you have a pot that has holes underneath so that the excess water can drain out properly.

Overwatering: If you water your cactus frequently, it can cause problems. If the soil is excessively moist, you may notice the appearance of a yellow hue on the moon Cactus. This is an indication of stress and the plant cannot survive in such conditions.

Underwatering: Too much less watering is also a problem for your cactus. At least, once a 

week sprinkle some water on your lovely moon. If you give water once a month or more, it will start turning yellow. 

Used water type: It’s possible the tap water you’re using is ruining the soil of your cactus.

Environmental jarking: If you’ve just bought your succulent, and it has begun to show a yellowish hue this could be due to a change in the environment.

Natural yellowness: There are cacti that appear green at first, but then turn yellow with time. If you’re not sure whether that’s the case for yours, head to the shop you bought the item and ask for their advice. You could also look up the species of the cactus you have.

Keep an eye on the plant every day. If the cactus is good and has no changes, then it’s likely all is well.

Too small pot: Yellowing is a sign of stress in succulents, the problem may be that the pot is too small.

How to get rid of yellowness

  • Invest in an inexpensive moisture meter, so you can precisely measure the level of moisture in the soil.
  • The soil should be regularly changed and fertilized, especially in the growing season (mid-spring to mid-autumn)
  • Invest in the proper soil as well.

Why is the Moon Cactus Stem Turning Brown?

Turning Brown

The moon cactus (Gymnocalycium mihanovichii var. friedrichii or “Hibotan”) is prized for its colors.

The plant is without chlorophyll, which means that instead of having a green body, it appears red, orange, or pink.

Root rot: The most commonly cited reason for a rotting, brown stem in the cactus plant is root decay.  When the stem begins to become brown, this typically means that it is decaying. A healthy stem is solid and green.

Overwater and poor drainage: The most typical cause for an eroding, brown stem in the cactus plant is root rot. This usually occurs because the plant is too watered or isn’t draining well, or both.

Pests: Fungal infections, such as bacterial infections, illnesses could cause the moon cactus’s stem and scion to change color.

Why is the Moon Cactus Turning Black?

Turning Black

Lack of light: The most common reason you’ll notice the Moon Cactus turn black could be due to the absence of light, which can cause weak growth and discoloration.

Overwatering: Also if you combine this with overwatering you will get this problem.

Temperatures:  This is more common in the winter when light levels are lower, temperatures are lower which causes your cactus to black and this cactus needs much less water.

How to get rid of blackness

It is still recommended to look for rot in the first step to be sure. If there’s no evidence of rot, you should look at the lighting conditions and at the very least, provide more indirect and bright lighting throughout the day.

So remove or cut off the black-affected part of your cactus, and let them grow from their intact part. And wait for a while until they have blown out again with their full aesthetic beauty.

Why Is My Moon Cactus Turning White?

Turning White

There are some causes why your moon cactus turns white. Here is why

#1 Cacti Are Exposed to Cold Temperatures

  • Cacti aren’t designed to stand up to cold temperatures.
  • When cacti are in areas where the temperatures drop below 50 F they may become white due to exposure to freezing or ice crystals that have formed on their needles as well as other parts.
  • It’s usually only temporary, but the cacti could be killed if subjected to cold temperatures for a prolonged time.

 #2 Cactus Is Under Too Much Sun Exposure

  • If cacti is placed in a spot that gets excessive sunlight, they’ll begin to appear white and look crisp.
  • The cactus gets sunburned due to the UV radiation of the sun. It kills the living cells that are on the skin.
  • It is dehydrated as a result of the water evaporated from its needles, leaves, or spines.

#3 Cactus Has Been in a Place That’s Not Well Ventilated 

  • If a cactus grows in an area that is not getting adequate ventilation, it could begin to change color.
  • This is due to the fact that cacti require plenty of airflows to keep their humidity levels.
  • If the cactus grows in an area that isn’t well ventilated, it could begin to appear white as the mold begins to develop on its surface.

#4 Cactus Is Overfed

  • The cactus could turn white due to the fact that it has been fed too much fertilizer. Cacti require fertilization extremely sparsely.
  • It is recommended to only fertilize every year.
  • If you’re making use of too much fertilizer there’s a good chance that this is the issue happening.
  • The scions and stems of the cactus will become yellowed if they’ve fed too many nutrients, and this can result in them falling off because of a deficiency of chlorophyll.
  • Rootstock stem can also appear burnt due to lack of ability to absorb sun no longer.

 #5 Cactus Has Been Watered Too Much or Not Enough

  • If the cactus is overwatered or not enough, the plant may become white. This is due to the fact that cacti require less water than many plants.
  • Cactus soil needs to dry between waterings, but certain varieties of cactus can live without water at all.
  • If the cactus is overwatered and turned white, it will then begin to die when the water evaporates off its stems. There could be a slimy layer on the outside of the pot in case this happens.
  • If the cactus hasn’t been adequately watered-or not received any whatsoever-it will be the stems and spines shriveled and turned to white.

#6 Cactus Has Been Attacked by Bugs

  • A white-colored appearance on a cactus can be caused by bugs like spider mites and aphids and mealybugs.
  • The pests place their eggs inside Cactus needles. They develop and then produce more bugs.
  • They then release honeydew, a chemical found on cacti leaves that encourages rotting mold to grow.  
  • A cactus that has been attacked by bugs will be covered with pink or white patches after it was eaten.

Why is the Moon Cactus Turning Red?

  • It’s completely normal If your Moon Cactus has its red hue, there’s no reason to be concerned.
  • Be aware that it could lose its color over time since it’s placed on the upper part of the cactus, so take advantage of it while you can.

Top 5 Reasons That Affect Color Fading in Moon Cactus

Top 5 Reasons That Affect Color Fading in Moon Cactus

It is important to note that a color change in a moon cactus can be indicative of an underlying problem. There are top 5 reasons associated with fading or color loss in the moon cactus, which you have to strictly observe to protect your cacti from any form of discoloration. Here are some reasons

Light Exposure

If you noticed that your moon cactus is gradually losing its vibrant glow, but it can be attributed to sun exposure. You should plan on giving your plant more light or shielding it from the sun.

Although the top graft can tolerate low light and survive under a shade, the green rootstock needs ample sunlight to grow well and support both its own and ball graft’s needs.

Be sure to keep your plant in the shade for extended periods of time. Exposing it to too much sun can dry out the scion and ruin it.

If you notice your cactus getting sunburns from sudden, prolonged exposure to direct sunlight, try replacing it with less direct sunlight. With gradual exposure and time, your cactus will be able to maintain the high temperatures needed for it to thrive.

Old Age/Corking

One issue that many moon cacti face is corking. Corking occurs as the plant ages and becomes more mature. Their skin will develop brown patches and it can be hard for people to touch them.

No matter how devoted some growers are, moon cactuses typically do not exceed 4 years of life.

The lifespan of the cactus is significantly shortened because the upper cactus outgrows the lower one and bites its juice.

If your rootstock is too weak or thin, it’s not carrying enough nutrients to the graft. When the rootstock of your graft becomes too weak and narrow it might not be able to distribute nutrients through the stem, leaving it pale and unhealthy.

As UA Campus Repository described “Unrooted rootstock can only be used with a moon  cactus which has an adequate supply of moisture and nutrients in storage to carry both itself and a scion through a period of several weeks until adventitious rooting of the understock occurs.”

The best way is to remove the dying plant and graft it on a new healthy one so it can continue its life span.

Over Watering

Cactus plants require minimal water and will thrive. Overwatering them, or letting them dry out for too long, can damage the roots which could cause them to rot, turning mushy and yellow.


The moon cactus was the perfect specimen of this succulent, until a bug crawled on it. The bug’s body left its own trail of ink that took away the plant’s green color. Now, it looks like a white mound with ink stains all over.

Cacti can be susceptible to pests; fungus growth in certain conditions, which can lead to white spots on the plant. This issue commonly occurs due to temperature changes, excess moisture, and lack of proper care.

In most cases, white spots on cacti are caused by bugs. The white spots can be protective shields of mealybugs or powdery mildew. Another reason for white spots on cacti is a virus called necrotic spot.

Soil/ Fertilizer

Moon cactus don’t need to be fed so often, but not feeding them enough will deprive them of the nutrients they need, resulting in unhealthy light white plants

Nutrient-rich, good quality, and gritty potting mix will work best for your moon cactus. Feeding them during their active state can help improve their chance of survival.

Is My Moon Cactus Dying Because Of Color Change?

Moon cactus are typically resilient, growing without any specific care. A change of color is not considered to be an indication of their death.

If your cactus’s leaves start getting yellow, droopy, and emitting an unpleasant smell, then it may be suffering from a physical condition that is weakening its root structure.  But if the plant appears to be all healthy and in good condition despite the color change, then there shouldn’t be any concern.

I insist that a change in the plant’s color is a sign of how well it is adapting to changes in its environment. If the color changes from less robust to vibrant as the intensity increases, then it’s a good sign that your plant has adapted to being exposed to more light.

However, sometimes this condition is a sign of a dying cactus. When it happens the plant has noticeably decomposed and usually has yellow or brown coloration. In addition to the above, it may have flaky or soft tissue as well as rotted roots–all signs of death.

However, you can save the portion that is unaffected by discoloration. If the rootstock becomes brown near the base and you want to save the plant by cutting away the damaged portion. The cut must be healed and is calloused prior to replanting.

Discolored moon cactus can recover depending on the severity of the damage. However, if the plant has been severely scorched, there is no chance of recovery.

But the rootstock, if it is still green, needs some saving by de-grafting or removing the sunburnt scion. Allow the top cut to heal and callous. 

But the rootstock, if it is still green, needs some saving by de-grafting or removing the sunburnt scion. Allow the top cut to heal and callous. over, then re-graft it to the rootstock.If the scion is green, you can wrap it in a moist cloth and keep it for replanting later.

You cannot redeem a rootstock, mushy and yellow, that has rotted to the point where the scion. The scion can be saved if there is not a lot of rotting, however. This will extend its life span and allow it to be re-grafted onto another healthy rootstock.

Related Questions

How much light does a moon cactus need?

Moon cactus require indirect sunlight that provides up to two hours of afternoon or morning light even in a shaded place that’s still bright, or next to a bright window. Be aware of the possibility of being burned, since they’re sensitive to intense sunlight.

Key Takeaways

There are so many reasons why your moon cacti are losing colors such as overwatering and under watering, stress, strain, excess light, lack of light, temperatures, humidity,  pests, and over- fertilization.

Moreover, too small a pot, insufficient micronutrients,  poor soil, poor drainage system are some more contributing factors of discoloring your moon cactus.

Anwar Hossain

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

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