Gymnocalycium Mihanovichii (Moon Cactus): Easy Care Tips

Moon Cactus is an adorable and colorful mutant cactus. It is a mutant cactus because it is a combination of two different types of cactus, Gymnocalycium and Hylocereus. These two types of cactus are actually being grafted together to form one new type of cactus.

The top part of the cactus is Gymnocalycium Mihanovichii. In the wild, these are typically a shade of green, but in markets, they are brightly colored. Unfortunately, all that color means that these plants are mutants that do not produce chlorophyll. Because they don’t produce chlorophyll, they will die as seedlings, and therefore, they need to be grafted onto a host plant. This is where the second type of cactus comes into the picture.

The bottom part of the cactus, which is the host cactus, is a species of Hylocereus. Interestingly, dragon fruit is a part of the same genus.

How to Identify Moon Cactus

Cactus Moon

This type of cactus is very easy to identify; it is an extremely popular option at lawn and

  • Roundheads with prickly spines garden stores, and you will see it everywhere. The significant features of this cactus are:
  • Bright colorful tops (pink, yellow, red, orange, or purple)
  • Compact size (they only grow up to 8 inches in diameter)
  • Produces offsets on its round top

Where Does Moon Cactus Grow

This cactus is a native of the desert areas of South America. They are frequently found in parts of Argentina, Paraguay, Brazil, and Bolivia.

Uses of Moon Cactus

When it comes to a versatile cactus, this is the optimal choice. Honestly, there is so much that can be done with these tiny, colorful plants; they really are one of the best ways to decorate with nature. A few suggestions are:

  • Plant them in a succulent garden
  • Place them on a windowsill
  • Use them as tabletop decorations
  • Add one to a bookshelf for a pop of color
  • Place them in a container or a terrarium with other types of cactus or succulents
  • Set several different colored cacti in single pots for a dramatic effect
  • Give them as gifts

How to Grow Moon Cactus from Seed

Growing a moon cactus from seed is a long and tedious process. It can take over a year to get any sign of growth. But, if you are determined to grow a moon cactus from the ground up, here are the steps you need to follow:

  • Fill a container with dry succulent potting soil mix
  • Place the seeds on top of the soil
  • Sprinkle the seeds with fine grit
  • Moisten the soil
  • Place the container in a warm location
  • Wait for germination
  • Replant the seedlings once they are large enough to move

Moon Cactus Growing Conditions

Cactus moon

This cactus has the typical needs of any succulent. They need sunlight, heat, and well-draining soil to survive and thrive.

When to Plant Moon Cactus

Spring and Summer are the best times to plant Moon Cactus.  These are the times of the year when there will be the best amount of sunlight and heat.  When kept in a container, they will require a new batch of soil every few years so that they get the nutrients they need.

How to Plant Moon Cactus

It is best to plant this cactus in a container that has many drain holes so there is no chance of standing water. Planting a Moon Cactus is a very simple process that includes the following steps:

  • Cut or pull off an offset from the main plant
  • Fill a container with succulent potting mix
  • Place the offset into the container (you can put part of it in the soil or just lay it on top of the soil)
  • Moisten the soil thoroughly
  • Allow the excess water to drain through the bottom of the container
  • Set it in a warm place with filtered sunlight

It must be remembered that this plant is a hybrid and the top part of it is grafted into another plant that will provide it with the chlorophyll that keeps it alive. If you want a healthy Moon Cactus that will have an extended life, it is a good idea to graft offsets into a new rootstock. To complete this process, you will need a grafting knife, gardening gloves (this is a spiky plant), and twine or rubber bands.

The really important part of grafting a cactus is that you choose the proper type of rootstock. When it comes to a Moon Cactus, the best rootstocks are Cereus Repandus and Hylocereus Trigonus.

Once you have gathered all your equipment and selected the rootstock and the Moon Cactus that you want to graft together, you can be working through the grafting process. These steps for grafting two cacti together are:

  • Decide what height you want the rootstock to be (you need at least three inches of rootstock).
  • Cut the head of the rootstock to the height you decided on.
  • Cut off the head of the grafted cactus (the scion) so that it and the rootstock are approximately the same diameters.
  • Match the tubes or dots (xylem and phloem) of the rootstock to the scion.
  • Tie the two plants together with twine or a rubber band. A little pressure is fine.
  • Wait for the plants to heal and grow together.
  • Water and care for the plant just as you would any other cactus.

Moon Cactus Water Requirements

The water requirements of Moon Cactus are typical of most succulents.  Since this plant is susceptible to root rot, it is best to use the soak and dry method when watering it.  The steps for doing this are as follows:

  • Fill a tray or a sink with a few inches of water.
  • Set the plant container in the tray making sure that the water is not so deep that it will run over the top of the container.  The point of watering in this way is so that the roots will soak up the water and the leaves will not get wet.
  • Let the plant soak in the water for fifteen minutes.  This will allow the root system to soak up water from the bottom of the container.
  • Take the plant container out of the water.
  • Place the plant container in a spot where the excess water can drain from the hole in the bottom.
  • Repeat this only when the soil around the plant is dry.

Moon Cactus Sun Requirements

This plant does not do well in cold weather, so it requires plenty of warm sunlight. It will need to be kept in an environment that is no colder than 48 degrees Fahrenheit. It will also need partial sunlight to partial shade throughout the day. If it gets too much sunlight, it will burn and die.

Best Moon Cactus Fertilizer

During the warm summer months of spring and summer, Moon Cactus can get a diluted feeding each week in place of one watering session. An excellent fertilizer for succulents and cactus is Miracle-Gro All Purpose Plant Food. This is a water-soluble option that can be mixed with a gallon of water to dilute it so that it doesn’t burn the plant’s roots.

Best Moon Cactus Companion Plantings

When it comes to having a great companion plant, Moon Cactus is the ultimate. This makes pairing it with other plants extremely easy, that is if you can narrow down your choices. To help whittle down your options, here are three amazing plants that will be perfect to set next to your Moon Cactus.

Kalanchoe Tomentosa ‘Panda Plant’

Kalanchoe Tomentosa ‘Panda Plant’

These may be the most adorable plants on our list.  Their leaves are green, fuzzy, and tipped with a chocolate brown; altogether, it does remind one of a panda bear.

What This Plant Needs


Use a balanced fertilizer diluted to half strength during the spring and summer months.


Panda Plants grow just fine indoors.  Heat and humidity are not an issue.  They can be taken outside during the warm months of summer and spring as long as they are kept out of the hot afternoon sun.


If kept indoors, place this plant in an area that receives medium to bright light.  If placed outdoors, keep it away from hot direct sun.


Panda Plants need potting soil that is sandy and will drain well.  It should also contain some volcanic rock known as perlite.


  • It is a plant that is easy to care for
  • It is a favorite for children’s rooms
  • It does not grow to be very large
  • It does not require a lot of water or fertilizer
  • It can live in lowlight conditions
  • It is easy to propagate from leaf or stem cuttings


  • It is toxic to animals
  • It is easy to overwater

Fairy Castle Cactus

Fairy Castle Cactus

This is a hassle-free and beginner-friendly cactus that adds an enchanting feel to garden spaces. It will be the perfect complement to the already quite dramatic Moon Cactus.

What This Plant Needs


Fairy Castle Cactus grows well with a cactus and succulent fertilizer during the spring.  It is important to remember that it will only need to be fed during the warm growing months and should not be fed during the winter.


Just like most other types of succulents, Fairy Castle Cactus does not handle cold weather very well.  For this reason, they should not be planted outside if you do not live in USDA Hardiness Zones 10 – 11.  If you don’t reside in either of these zones, it will be necessary to plant them in a container that can be brought indoors during cold weather.


Fairy Castle Cactus has a need for light that is similar to other cacti; namely, it likes a lot of it.  An established and mature plant that is kept outdoors can handle full sun.  A plant kept indoors needs to be kept in the sunniest place possible, preferably a south-facing window.


These will grow best in soil that is coarse and sandy.  Soils such as pumice, gravel, sand, perlite, and bark should be used; whereas, soils such as clay or peat moss should never be used with these plants.


  • Grows indoors very well
  • Drought tolerant
  • Prefers lots of direct sunlight
  • Does not need a lot of water
  • Does not need a lot of fertilizer


  • Slightly toxic
  • Can grow up to 6 feet tall
  • Susceptible to mealybugs, mites, and gnats
  • Does not tolerate cold weather

Bunny Ears Cactus

Bunny Ears Cactus

This type of cactus is a pleasing sight. Its flat pads form into the shape of floppy bunny ears that are green and covered in small pricks. They can also produce yellow flowers and purple fruits.

What This Plant Needs


Use a liquid fertilizer that is rated at 20-20-20 to give the plant a little help as it grows. You will want to dilute the fertilizer to one-half its strength. Also, remember to only fertilize a cactus when it is in its growing season.


This cactus likes it hot. It can handle temperatures as high as 100 degrees Fahrenheit without any issues. It can also deal with temperatures as cool as 45 degrees Fahrenheit.


Your Bunny Ears Cactus will need plenty of bright, direct sunlight for at least ten hours each day.


This cactus will grow best in potting soil that is well-draining. Use anything that is designed for use with a cactus or succulent.


  • It is drought tolerant
  • It does not need much water
  • It is easy to propagate by replanting a fully grown pad
  • It can be grown indoors and outdoors


  • It can grow to be very large (6 feet tall and 3 feet wide)

Moon Cactus Diseases and Common Problems

This cactus has many of the same problems that are common amongst succulents and cacti. It is susceptible to mealybugs, scale, and root rot.

Moon Cactus Treatments and Maintenance

Moon Cactus Treatment


If you notice white fluff growing on your plant, you may have a mealybug infestation.  To rid your plant of these pests, apply rubbing alcohol to any places on the plant where you see the white fluff or the actual insects.  There is also the option of spraying the plant with a solution of diluted dish soap and water.

Mealybugs can also be hiding in the roots of the plant.  If this is the case with your String of Bananas plant, it will require that you remove the plant from its container, shake off the soil, wash the roots with diluted alcohol or soapy water, allow the plant to dry, and then, replant it in new, fresh soil.

Note: Ridding your plant of mealybugs may take a few treatments over several weeks.


These are tiny insects that will appear as small, brown bumps on your succulent.  If you notice these, remove the visible insects and start cleaning the plant with diluted alcohol or soapy water.  If the roots of the plant have been infested, you can clean them in the same manner that you would in the case of a mealybug infestation.

Root Rot

The signs of root rot in a plant are yellowing leaves, wilted leaves, mushy leaves, and/or a rotting smell.  If any of these signs appear in your plant, you need to take action immediately.  You will need to let the plant dry out, remove any rotten parts of the plant, and let the plant callous. If these treatments don’t work, you will need to add sulfur to its root system or behead the plant as a last resort.

Moon Cactus Repotting Instructions

This plant prefers being crowded in its container, so it shouldn’t need to be replanted very often. If you do need to re-pot your Moon Cactus, the process is simple.  Here are the steps:

  • Find a container that drains well
  • Add some succulent potting soil to the container
  • Gently set the plant into a hole in the potting soil
  • Add more potting soil, if necessary
  • Pat down the soil and make sure the plant is secure in the soil
  • Set it in an area where it can get indirect sunlight until is established

Where to Buy Moon Cactus Seeds Online

If you are interested in propagating one of these plants from seeds, try this online shop.

Where to Buy Moon Cactus Plants Online

There are plenty of wonderful online shops where String of Bananas plants can be purchased.  These five online shops offer a great selection.


Question: Are Moon Cactus Toxic?

Answer: No, this type of cactus is not known to be toxic to humans or animals.

Question:How Long Do Moon Cactus Live?

Answer: This type of cactus usually only lives for a few months to a few years. With proper care, it can actually live up to a decade.

Concluding Thoughts

Cacti and Succulent lovers swoon for these vibrant plants. They are easy to care for and easy on the eyes. So, if you are looking for a way to enhance your garden or your home, try adding a few of these.

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