All You Need to Know About Moon Cactus

If you are a succulent collector, there are unlimited varieties of several different forms, shapes, colors, sizes, and textures available.

The Moon Cactus is another unique succulent that is not only beautiful but has some really peculiar characteristics.

So, let’s cut to the chase and discuss all you need to know about the Moon Cactus and its cool characteristics.

Moon Cactus Origins

The Moon Cactus belongs to the Cactaceae family, and its scientific name is Gymnocalycium mihanovichii.

Numerous other names are also used for it, such as Red Hibotan, Red Cap, Hibotan Cacti, and Ruby Ball.

First discovered in 1903 by Czech ethnographer, explorer, and botanist Alberto Vojtech Fri in the South American regions. Later in 1905, it was named Echinocactus Mihanovichii, and in 1922, it was added to the Gymnocalycium genus.

It grows in arid regions of Bolivia, Paraguay, Brazil, and northeast Argentina and can grow up to 500 meters above sea level.

What Is the Moon Cactus?

When you go out to buy a Moon Cactus for the first time, you should know that it is actually two plants combined into one. 

Normally, Moon Cactus are mutant houseplants that lack chlorophyll, which accounts for their vibrant colors, ranging from neon yellow to hot pink.

Since they can’t survive without chlorophyll, they have to be planted onto another cacti’s rootstock.

Most frequently paired with dragon fruit (Hylocereus undatus), but Trichocereus spachianus and Cereus peruvianus can also be used. 

Moon Cactus Grafting

Although a grafted cactus tends to be weaker than those that develop their own roots, in some cases, it is the only method to preserve a nice specimen.

Grafting enables the recipient plant to absorb the necessary nutrients to survive from the root system of the host plant.

Since moon cacti don’t have chlorophyll, they need it from somewhere else to be able to survive.

These plants can only live for over 6 months, and if you are lucky, up to a year. Moon cacti struggle to survive on their own; it’s almost like it’s designed to fail.

The green part underneath the vibrant succulent that resembles a stem requires sunshine to produce chlorophyll.

However, the upper bright-colored part lacks chlorophyll and, therefore, cannot tolerate the sun.

Both the parts of the grafted cactus exist and grow together, albeit in a parasitic relationship. 

How to Grow a Moon Cactus?

If you are accustomed to growing different cacti and succulent species, the caring and growing of the Moon Cactus is almost the same as other cacti and won’t cause any problems.

But even with appropriate care, they can only survive for a few years at most. But their uniqueness and beauty are worth every effort.

When you buy a Moon Cactus, you will be provided with any required information regarding its care and cultivation.

If it doesn’t come with any instructions, you will care for it like you would any other cactus. Let’s get into the details of the growth and care instructions of a Moon Cactus.


Being an albino plant, the Moon Cactus lacks chlorophyll. As a result, it depends on the host cactus for sustenance.

The ball tops don’t like direct sunshine and require more shade than other cacti species. On the other hand, the rootstock at the bottom needs sunlight to survive and produce nutrients. 

The optimal conditions for these cacti are areas with brilliant illumination and only a few hours of morning sunlight.

Direct sunlight will cause the vibrant colors to fade and eventually kill the ball top; therefore, it is important to place the plant in a shaded area.


Similar to many other cacti, the Moon Cactus also prefers a dry period in between watering, almost to the extent of mild wilting.

But whenever you do water the plant, make sure to water it thoroughly. Additionally, the plant will visibly thicken up.

The cactus shouldn’t be left in areas of constant wetness or standing water because this might lead to the development of root rot.

The plant can, however, require regular watering during the summertime, particularly if it has been relocated outside.

Small-potted plants just require weekly watering. The plant doesn’t require any watering during the wintertime; occasional misting should be enough. 

Soil & Fertilizer

The optimal cactus mix has a low pH and is rich and quick draining. Ensure that the soil satisfies the requirements of the rootstock at the bottom.

Your Moon Cactus plant doesn’t require routine fertilization, but you should give it a monthly dosage of cactus fertilizer during the growth period (April to September). Feeding should be stopped during the wintertime slumber.


The ideal temperatures for the ball top and the rootstock are both different. This cactus likes low humidity levels, like the majority of succulents.

The Moon Cactus can endure extended droughts and flourishes in desert-like environments.

It can thrive in temperatures about 70 °F (21 °C) indoors, but you need to keep it away from conditions below 40 °F (4 °C).

A thin sheet or blanket can be highly effective wintertime protection for moon cacti since frost would kill them.

The ideal temperature limit during the wintertime is around 50 – 60 degrees Fahrenheit. Borderline temperatures have the potential to kill the upper section while preserving the rootstock.

Moon Cactus Propagation

Some moon cacti have colored parts that sprout tiny, propagable offshoots.

These can be grafted onto the rootstock of other cacti like Trichocereus spachianus, Hylocereus trigonus, or Cereus peruvianus.

Follow the following steps to successfully propagate your Moon Cactus:

  • Use any of the aforementioned cacti for the rootstock.
  • Cut the top of the rootstock, so it is just a few inches tall.
  • Always use a clean, sterilized knife while doing so.
  • Cut off a piece of the ball top you wish to propagate. 
  • Place the ball top’s offshoot over the rootstock that you have prepared.
  • Using strings or a rubber band, join them together to hold it in place.
  • Wrap it vertically completely around the plant and pot.
  • You should be able to see the plant start to grow together as one in approximately 6-8 weeks.
  • Be careful and watch the plant closely throughout this period for any bugs or rot.

On certain mature plants, the top Gymnocalycium automatically sends off offsets that group together around the parent plant like satellites.

You may take these out and plant each one separately as a Gymnocalycium plant, but it will still need a hosting green cactus to get its chlorophyll. The Gymnocalycium will perish if it lacks that host.

Repotting the Moon Cactus

Although these plants don’t grow quickly, they should be replanted every 3 to 4 years to give them new life in new soil. 

  • Repotting ought to take place ideally in the summer growing period. 
  • Before repotting a cactus, ensure the soil is completely dry and carefully remove the container. 
  • Be careful to eliminate any rotting or dead roots when removing the old soil from the roots. 
  • Any cuts or wounds should be treated with an antifungal. 
  • Spread out the roots as you repot the cactus, then put it in its new container and cover it with a good quality cactus-mix potting soil.
  • To minimize the chance of root rot, let the plant go for about a week without any water, and then start watering it sparingly.

Due to the increased danger of root rot and repotting-related problems (including transplant shock), Moon Cacti are significantly better off being pot-bound for a number of years.

Repot it only if it is absolutely necessary.

To reduce the chance of transplant shock, water the plant for 24 hours before making any root-related adjustments.

Increase the amount of grit and perlite in the lowest part of the new soil for plants located in darker areas to reduce the danger of overwatering.

Diseases and Pests

Despite the fact that Moon Cacti are mostly pest-free, watch out for any signs of root rot, scale, or mealy bugs.

Southern blight, powdery mildew, rust, botrytis, leaf spot disease, and root rot are some of the most common diseases that affect the moon cacti.

Methods for Making Moon Cactus Flower

There is typically no need to coax blossoms from the Gymnocalycium mihanovichii scion because the yellowish-green blooms are undetectable.

Since the bottom rootstock and the grafted scion are two separate species with distinct blooming patterns, you might occasionally discover this cactus producing two distinct types of blooms.

However, if the plant bears no blooms at all, it is not an issue.

Typical Issues with Moon Cactus

The Moon Cactus is a hardy, simple-to-grow plant like most potted plants cacti; however, there are a few things to look out for:

  • Excessive watering causes the host plant to collapse.
  • Separating of the ball top due to varying growth rates.
  • Excessive sunlight causes the ball top’s color to fade.
  • Edges of the vibrant scion turn brown due to too much sunlight or too much water.

In Conclusion

Moon Cacti are hard to resist. In order to complete and perfect your collection of cacti, you should unquestionably add it.

They are decorative houseplants that are tiny, vibrant, and very simple to grow.

These cacti will flourish if you can mimic their natural environment and finally give birth to adorable blooming.

Apart from basic cactus growing guidelines, you only have to be careful with the amount of sun it receives.

Just pay attention to both the parts of your moon cacti and cater it accordingly. Your plant will surely survive and grow healthily and happily.