Top 11 Reasons Why My Moon Cactus Turned Brown? (7 Solutions)

Why My Moon Cactus Turned Brown?

Moon Cactus ( Gymnocalycium mihanovichii ) is sometimes referred to as Hibotan cactus or ruby ball cactus or a cactus with star-flowered flowers. Moon cactus is a mixture of two cacti that were interspersed. The top cactus is vibrant Gymnocalycium mihanovichii and the bottom cactus is green and could be any type of cactus. The ball of cactus is typically between 2.5 to five centimeters (1″ and 2″).

The most common reason for this is the age which is called corking. There are some more reasons like lack of light,  rotting, Stem Turning Brown, Rotten Below, Bacteria or Fungus, Scales, Mites, Plugged, Tanned,  and climate change, which can cause moon cactus to turn brown.

The best method to stop your cactus from becoming brown is to ensure that the environment it is in is suitable for healthy growth of the plant. Make sure you have clean, loose and well-drained soil.

Inspect new plants for quarantine and check them for disease and pests before exposing them to other plants.

Why Is My Cactus Turning Brown?

A Moon Cactus may turn yellow due to the same reasons that it may turn white, such as damage from frost, sunburn, and so on.

1. Corking

In addition to yellow Cactus plants can become brown. The main reason is age, which is known as corking. Corking occurs naturally as an cactus matures.

# Corking is an essential component of the growth process in cacti. The base of the cactus is turned brown and then hard to support the other cactus structures. Corking is like the process that occurs in plants over time that at first as they grow they’re green, but as time passes they develop a color similar to wood, and then become more robust to support the plant’s structure. This is the reason older parts of cactus begin to turn brown is beneficial and is essential for its lifespan.

## The brown sections are also present elsewhere on the plant
: It’s not unusual for the healthy, natural cork to develop in other areas of the plant which don’t include the base. This is due to the fact that many commercially grown cacti can be propagated by cuttings, and so it’s possible for a new cactus to belong to an existing one, which was cut and propagated independently. The cuttings keep the genetic code and get corked earlier and in unusual locations.

brown sections are also present elsewhere on the plant

### premature corking:  When the soil becomes overly rich or the air is too dry, or it is exposed to excessive sunshine, the plant could become brown before it is time, which could happen if it is not properly watered.

It is located at the base of the plant, where it touches the soil. It is able to grow up in a slow manner or remain in one place. Corking provides the plant with the appearance of wood. The plant is otherwise healthy and soft to the feel.

2. Lack of Light and Lack of Water

The Moon Cactus can be yellow due to a the lack of light, and also of water, or an amalgamation of both these factors.

3. Moon Cactus Stem Turning Brown

The plant lacks chlorophyll. This means it’s instead of being green, it has a body. It also doesn’t produce food, and in order to survive, it has to be grafted onto the stem of a different Cactus. Most often, it is transplanted onto the stem of a Hylocereus spp. However, this is a mistake since these species are typically weak and are prone to developing root rot.

Hylocereus species grow quickly and are climbing plants. This is why the stems are a bit soft and brittle. They weren’t designed to support another cactus however, they are commonly utilized to support a moon Cactus. Hylocereus species can only be found in subtropical and tropical climates, which are the same as moon Cactus. This is why moon cacti are typically planted indoors in containers.

4. Something’s Rotten Below

If the stem begins to turn brown, this typically means that it is decaying. A healthy stem is stable and green. The most typical cause for the stem turning brown and rotting in a cactus plant would be root rot. It is usually due to the plant being excessively watered, is not draining well, or both.

Unfortunately, this could mean an end to your lunar Cactus. If the roots are damaged they won’t be in a position to regenerate but, it’s easy to check this. Remove the plant gently from the pot, or even dig it up then take a look at your roots. 

If they’re slimy and brown, the plant is likely to be already dead. If they’re solid and white, consider planting them again in fresh clean, sterilized soil in a fresh pot or in a different spot within the yard.

Root rot-infested plants can end up being difficult to rescue as the rot begins inside the cactus, and then works through the cactus, therefore the symptoms usually are not apparent until the rot has advanced.

It is possible salvaging a cactus that has the advanced stage of root decay by cutting out any evidence of rot and some healthy tissue to ensure that it does not cause. Make use of a clean knife and scrub it clean using ruby alcohol between cuts. Apply sulfur powdered (buy from to wounds.

  5. Bacteria or Fungus

Fungal infections and other diseases could also cause the stems of your moon cactus to become brown. Most often, the browning occurs in different areas of the plant. The plant will be  feel soft and mushy.

  6. Scales


Scales are tiny insects that look like marks of brown on the cacti due to their tough brown coverings. Scales feed on the juices of cacti plants, weakening plants and making it appear yellow. Spray your Cacti with stream water to get rid of scales or wash them with a diluted solution of detergent. Use malathion insecticide ( buy from for large infestations. You can also kill scale by using a cotton swab to apply vegetable oil to each scale. This cuts off the scale’s air supply and suffocates.

7. Mites


Red mites are tiny insects with a reddish color. They are small enough that it’s easy to find their webs than the insects themselves. They are characterized by white spots that change to dark brown, and are usually found at the plant’s top. If untreated, mites will kill your cactus, devouring the entire outside layer of tissue of the plant. Infuse cacti from above using the forceful flow of water to eliminate mites.Miticides ( purchase here) can be used for large infestations.

 8. Plugged


The appearance of brown, firm-like bark at the top in a plant that is healthy is an indication of plugging. It is a natural process of aging for the cacti. Capping always begins at the bottom of the cactus and then moves upwards. If a cactus becomes in a brown hue from the top down it’s an indication of sunburn or another issue.

 9. Tanned


The mild sunburns appear in the form of a white discoloration. Burns that are severe appear as brown marks on the burned surface. Cacti with brown scars suffer permanent damage. If the plant is only showing white discoloration, you can treat it by moving it to shade. Cacti not accustomed to the sun must adjust by exposing themselves to the all-day sun for a short period of time every day, and then gradually increasing exposure over weeks.

 10. Climate Change

Cacti are usually planted in different environments from the region they originate in. Also, in a shop and in the greenhouse temperatures differ from those in an apartment. This is the reason why moving a cactus will always cause a shock. The variation in temperature, air, and humidity may cause it to suffer.

11. Maintenance Errors

A lack of maintenance can expose the cactus plant to fungi or bacteria. Usually, it’s:

  1. Lack of protection in the cold winter months (risk from frost).
  2. A sub-par substrate.
  3. Poor healing of wounds.
  4. Lack of air circulation (exposure to the drafts).

How to Fix This Brownish Issue?

If above all these happen with your cactus, you just have to pay attention to know what symptoms you have and how to solve them. Here we leave you some  ideas for their treatment.

If it’s totally dried (brown or yellow and melts when you touch it) or is completely black or soft It is likely that the cactus has become dead or dying and it’s hard to rescue it. However, If only certain parts of the cactus have been affected by this or if it is suffering from bugs, it could be more attainable to bring it back.

You will only require new soil, some gardening tools, a pot or container, and follow these tips:

1. Water the Dry Cactus 

dry cactus

With the right amount of water, that is, give it sufficient water but do not overdo it. You’ll notice the need for watering when the soil is dry. To check this, place your finger or wooden stick in the soil for 2 cm deep and see whether it’s dry. The amount of water you need to pour is connected to the time of year. Normally, though it is contingent on the location and weather, between March and September, the garden should be irrigated at least twice per month, and from October until February, every month, once.

Don’t overcompensate by watering more often than you ought to, especially in the event that this cactus was underwatered for a while. just return to your normal routine of watering and the yellow color will be back to normal.

According to the University of Arizona Pinal County Cooperative Extension Even plants with a low water requirement, like cacti and agaves, need water from time to time, especially in these times of drought.

2. Prepare New Soil

 If you have a rotten cactus, it is necessary to get rid of the accumulated water or find a new soil that has no accumulation of disease or pests. It is recommended to mix it with garden soil and peat (carbon-based material) and volcanic sand or coarse to ensure the plant can have an effective drainage system that can prevent the plant from drowning.

new soil

The most suitable soil for moon cactus plants is an aerated sandy soil which allows the water to drain easily. The addition of small stones or pebbles to a potting mix could make a suitable cactus soil. As with most succulents, cacti favor an potting mix that is neutral to acidic.

3. Check the Environmental Temperature

It is a good idea to put it in a room that is ventilated however it is not one that will get cold drafts, particularly in the winter.

4. Change It from a Pot or Container

If it’s rotten and the soil becomes dry and difficult to wet while you water it since it’s ineffective soil. It’s also crucial to remove dead roots when you repot because it’s too dry or wet. Keep in mind clay pots are essential to the proper hydration and ventilation of the plant.

5. Fertilize

If you choose to use a high-quality mix of cactus, the soil must be rich in nutrients. It is advised to choose one that is not high in nitrogen because of the requirements of Cacti. But, a monthly fertilization program in the spring and summer months can encourage the growth of the transplanted plant. Select a cactus fertilizer that is organic and mix it in accordance with the directions of the manufacturer.

Over-feeding of fertilization can cause the plant to become weak and yellowed. Make sure you don’t fertilize your moon-cactus in the winter or fall seasons.

“Let the water drain off completely before adding the cactus fertilizer.”

6. Temperature

Moon cactus plants like warmer temperatures and room temperatures should be optimal. Put your Hibotan plant next to an open window to provide it with the warm environment it needs to flourish; make sure to protect it from the hot sun. Starflower cacti thrive in temperatures ranging from 64degF up to the temperature of 77degF (18-25degC).

If you are growing your moon cactus inside, be sure to keep it out of cold drafts, like open windows, air conditioning, and direct heat. Moon cacti are not able to be able to withstand temperatures that are below 48degF (9degC).

7. Humidity

The Ruby Ball Cactus plant is fairly simple in its water requirements. Cactus houseplants are small and thrive in moderate humidity. However, they also do with ease in conditions of low humidity.

To keep the canopy of red, pink yellow, or orange cacti healthy and vibrant,  You can mist them frequently. Misting can provide the required moisture, without soaking the soil. Maintaining high levels of humidity during the winter months by misting,  your Cactus can also be beneficial. From October through February, it is not recommended to feed the moon Cactus plants.

Rick Gibson, Extension Agent, Agriculture stated that During the wintertime, with cool temperatures and enough humidity to slow water demand, all plants will need less water than they do during the summer months

Related Questions

How Do I Know If My Moon Cactus Is Dying?

If the stem begins to darken, this generally means that it’s decaying. A healthy stem will always be robust and green. The most frequent cause of the stem turning brown and rotting in the cactus plant is root rot. It is usually due to the plant is too watered or is not draining well or both.

Why Is My Moon Cactus Pale?

Moon cacti lose color when their condition is not optimal. There are four main reasons moon cactus’ colors change as time passes:

  • 1) light exposure,
  • 2) insufficient nutrients,
  • 3.) excessive watering and
  • 4) older age.

These causes could cause deaths to the plant, if unsolved.

How Much Light Does the Moon Cactus Need?

A moon cactus requires lots of indirect and bright sunlight. The top grafted plant is somewhat shade-tolerant and will not thrive when exposed to direct sun. The cactus that has a green stem typically will require more sun. Therefore, to have the healthiest moon cactus you must have the perfect balance of light.

The ideal spot for a cactus moon is in an area with plenty of light in your house. A windowsill that faces east or west can provide ample light as well as less direct sunlight. If your moon cactus grows located in a room that is south-facing you should keep it from windows to avoid it from burning.

If you see parts of your cactus’s ruby ball changing color (bleached) or showing signs of wounds, take them out of direct sunlight. The plant’s color change could be due to being exposed to excessive sunshine.

How to Regraft a Moon Cactus?

Moon cactus must be grafted again when you notice the shiny top starting to split from the green substance. This is the best way to ensure the health development of the moon cactus.

  1. Sharp knife to sterilize it and cut off the bright top of the Cactus.
  2. Remove the top layer of the broth that is green.
  3. See the circular the vascular tissue on both sides of the cactus, the pattern as well as the cactus ball that is colored.
  4. Put the two pieces of the cacti on top and line up the two vascular circles.
  5. To hold the cactus ball in place, put rubber bands around the cactus as well as around the bottom of the pot.
  6. After a couple of weeks, the two different parts of the cactus may begin merging to create one plant.

Anwar Hossain

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

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