How to take care of Moon Cactus?

The moon cactus stands out with a brightly colored ball-shaped flower. You have to take care of it just like any other cactus!

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Kelly Adams

May 16, 2021

How to take care of Moon Cactus? Water, Soil, Sunlight, Humidity, Repot, Propagation, etc. Thumbnail


What makes a moon cactus different from other succulents? It’s their beautiful bright colors that make them stand out in the cacti family. You can recognize a moon cactus by the round-shaped flower like the thing they have on top of the cactus stem.

The moon cactus needs indirect bright light. The ideal temperature level is 65°F to 75°F (18°C to 24°C), with ideal humidity being average. It blooms with brightly-colored flower. Grown via grafting, these non-toxic cacti need minimal to no fertilizer, well-draining acidic to neutral succulent soil.

Moon Cactus 101

The color of the Moon cactus ball is a result of having no chlorophyll! So, this part cannot produce its own food. This is why you’ll never see a moon cactus ball without a stem. They need a cactus stem to survive and this is done via grafting.

A moon cactus exists because its ball is attached to a host cactus stem. And just because of its bright ball, the moon cactus is also known as the Ruby Ball cactus!

Side view of colorful moon cactus balls

Botanical name: Gymnocalycium mihanovichii Plant type: Herbaceous perennial Soil type: Well-draining succulent soil (a cactus soil mix is preferable) Blooming: All the time, year-round (saturated yellow, orange, and red colors) Hardiness: USDA Zones 11-12 Native Region: South America Toxicity: It is not toxic for animals or humans.

Caring for the Moon Cactus

The moon cactus can be taken care of just like other cacti!

  • Ideal soil: Well-draining cactus mix
  • Drainage Needs: Requires good drainage
  • Water Requirements: Needs more water in growing season during April-September. Water it when the topmost layer runs dry.
  • Sunlight Requirements: Bright, indirect sunlight with partial shade
  • Temperature: 65°F to 75°F (18°C to 24°C)
  • Humidity: Room-temperature humidity
  • Ideal pH: Acidic to neutral
  • Frost-Resistance: Low, better not to leave it outside during harsh winter season
  • Fertilizer: A diluted fertilizer every month during growth season
  • Pruning: Any dead offsets must be pruned before they infect others
  • Propagation: Cannot be propagated, it can only be grafted
  • Repotting: Only during the growing season, when the soil is dry
  • Toxicity: Non-toxic for animals and plants

1. What is the Ideal Soil for the Moon Cactus?

The moon cactus requires a well-drained, regular cactus mix.

The moon cactus requires good drainage. It is essential to give it a shallow pot that provides good drainage. It should be planted in a pot that has holes so that drainage becomes easier. Before adding soil to the pot, make sure to place some gravel or rocks at the bottom.


The moon cactus is a typical cactus plant!

Remember that the moon cactus ball is planted on top of a regular cactus. So the soil requirements meet that of a typical cactus.

2. What are the Sunlight Requirements of the Moon Cactus?

Place your moon cactus in a spot with bright, indirect sunlight!

Place the moon cactus in a bright space with indirect sunlight. Never place the moon cactus in direct sunlight, especially for a long duration to stop indirect light. It is ideal when there is some sort of shade above the plant to stop the moon from leaving the moon characters outside in the winter.

Your moon cactus may freeze under a temperature of 40 degrees. Always bring them inside because they may get frozen.

3. What is the Humidity Requirement of the Moon Cactus?

The moon cactus prefers just slight humidity and moisture!

You don’t need to be strict with the humidity needs of your moon cactus. These succulents can adapt to any environment. Be it low-humidity indoors or high-humidity outdoors.

To keep the moon cactus ball fresh, you can mist it from time to time.


Keep the season in mind before misting!

In winter, mist your moon cactus instead of watering. This will maintain good humidity and prevent your plant from getting frosted.


Be careful when you mist your plant. You need to check the soil first. If it’s even slightly damp, wait for it to dry before you give your moon cactus a mist!

4. How Should I Water the Moon Cactus?

Water your moon cactus every time the base of soil runs dry. Don’t overdo it!

The moon cactus requires infrequent watering during summer. You will have to be mindful of the climate. Keep your plant indoors when it’s raining. During the cold season (October-February), don’t water your moon cactus at all if it’s old. For a younger moon cactus, water only when you feel the soil base is dry.


Watch out for these overwatering signs!

If the soil is coming out of the pot, it may be a sign of overwatering! Your moon cactus will wither and sag from too much water. Eventually it will destroy both the stem and the flower.


Keep an eye on the weather

When it’s hot, your moon cactus will need watering more frequently. However, the opposite will be true either during the winter or when it’s cooler. Always check the base of the soil to be sure of watering.

5. How to Fertilize the Moon Cactus?

The moon cactus only needs a tiny drop of fertilizer during the growing season.

The moon cactus does not require much fertilizer. However, its growing season is from April to September. During this period you can use a common cactus fertilizer. A drop every month should suffice.

Thinking of buying fertilizer for your moon cactus? You’ll love this all-purpose plant food from Miracle-Gro!

Your moon cactus will love this all-purpose plant food from Miracle-Gro! Use this fertiliser once after every 7 or 14 days!

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6. How to Prune the Moon Cactus?

The moon cactus doesn’t need pruning unless you see many pups!

Roots that look dead or diseased need to be removed immediately. Pruning is necessary before you begin to repot your moon cactus.

A potted moon cactus with many stems

7. How to Repot the Moon Cactus?

The moon cactus doesn’t require repotting often, except in the growing season.

The moon cactus does not need to be repotted often. You may need to repot it only during the summer.

Before repotting the moon cactus Make sure the soil is not wet. The soil has to be dry when you’re taking the plant out. Inspect for any brown and withered roots. These are the dead ones and need to be removed safely. If the plant has any sort of test characteristics, used as an insecticide spray on it before repotting.

After repotting the moon cactus Do not water it for at least a week. You need to give its roots some time to get used to the new soil. When repotting the moon cactus, pull out the plant using the stem and be careful not to touch the ball. Make sure you plant it at the same height as it was before.

Things You Should Know About the Moon Cactus

Although the moon cactus is grafted, caring for it is similar to a regular cactus!

1. How to Propagate the Moon Cactus?

The moon cactus needs to be grafted on another host cactus!

The moon cactus is a grafted plant and cannot be propagated by using offsets alone. Sooner or later, the pups will need a host. So this is where the grafting technique comes in.

In grafting, you take the moon cactus ball off from the parent plant. This ball is then placed onto another sliced host cactus.

These are the basic steps for grafting:

  1. Arrange for the host plant. This plant would be the one on which you will be placing the ball or flower of the moon cactus.
  2. The host plant needs to be sliced with a sharp knife.
  3. Pluck out the moon cactus flower balls and place them on the sliced area.
  4. Gently squeeze to fix them but apply as little pressure as possible.
  5. With time, the ball will gently form firm roots on its new host.

Remember to sterilize your knife before slicing the host cactus! To successfully graft the cactus, look for a circular shape on both the host cactus and the ball. Both these circles should touch each other when the ball is placed on top.

2. How toxic is the Moon Cactus?

Feel free to place your moon cactus anywhere!

Moon cactus in a pot beside a laptop

The moon cactus is non-toxic which is why it is safe for both animals and humans.

What are common issues with the Moon Cactus?

The zebra succulent is a tropical houseplant that enhances the beauty of the room but requires little care to grow!

Common issues with Moon Cactus include a leaning cactus stem, A brown or broken cactus stem, yellow cactus stem and pests

1. A leaning cactus stem

You can use a sterilized stick to support a leaning cactus. Its posture may become a bit stable but if it doesn’t, take out the plant. Inspect its roots to see the underlying problem. The reason behind the problem could either be overwatering or underwatering.

2. A brown or broken cactus stem

It is important to check the stem because the ball will not survive without it. When the stem of your moon cactus begins to turn brown, there may be fungus in the pot or the plant.

In the case of fungus, the stem turns soft and you won’t be able to save the plant. But if the balls are still fresh, you can remove them. Leave them to dry and attach them to a new, sliced host cactus.

Also, make sure you do the hosting in a clean and new pot. Otherwise, the new plant may catch the same disease in a matter of weeks.

3. A yellow cactus stem

The stem of a moon cactus always has to be green. If it begins to turn brown, there’s a high chance of root rot.

Root rot is a result of overwatering the soil. It may be the case that your pot isn’t draining out the water properly either. To save your moon cactus, remove the plant from the pot immediately. Check for slimy texture in the roots. Saving a moon cactus with slimed roots can be impossible.

To effectively repot a plant you would need a very clean pot. Sterilize it first to make sure it is free of germs and bacteria. If a plant withers, saving it by repotting is highly unlikely.

4. Pests

The moon cactus is naturally good against pests. Although you may need to use insecticides in case of mealybugs!


The moon cactus is a grafted plant that requires well drained cactus mix soil. Place it in a spot where there’s bright indirect sunlight. For proper care, this grafted cactus needs a temperature of 65°F to 75°F (18°C to 24°C). It prefers low humidity so place it indoors and fertilize it once a month to boost growth.

Feeling charmed by the moon cactus? Check out our post about the most exotic succulents!.

Which are the most exotic succulents in the world? You will love each one of them

Succulents are trending all over the world, while some are very common others can be quite the opposite. Read ahead to learn about rare ones.

Kelly Adams Picture

By Kelly Adams

Easy Succulents Founder

My name is Kelly and I'm the the founder of Easy Succulents! I'm fascinated by this wonderful plants and I want to share with the world everything I know about them!

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Kelly Adams Picture

Kelly Adams

Easy Succulents Founder

My name is Kelly and I'm the the founder of Easy Succulents! I'm fascinated by this wonderful plants and I want to share with the world everything I know about them!



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