Moon Cactus Size | 4 Problems Everyone Has About Them |

Knowing moon cactus size is important when choosing a pot or planting location for them. Therefore in this article I am going to write about the maximum size of this amazing plant and more interesting facts. 

Moon Cactus Size

How big do moon cactus grow

Generally, you could spot the  moon cactus in various heights. Their heights  will entirely depend on the rootstock.

Having said that, moon cactus would stop their growth when they are about 4 inch (10 centimeters) in height.

On the other hand, their diameter would be 1.1 and 1.9 inches (3-5 cm). Apart from that, they would consist of 8-14 slightly notched ribs as well. They would further  have narrow edges. 

Grafted moon cactus size

The size of a  grafted moon cactus would be small.

Their grafted tops would be about 4 inches in width Further you could spot some  individuals which could be larger than the size of a golf ball as well.  

Moon cactus lifespan

Moon cactus’s life span would be roughly around one year to three years. However, this is an average estimation.

There could be some moon cactus which could stay longer than that, like for five years. On the other hand, there could be some moon cactus which will live for a few months.

If we consider the cactus in general, they will live for about 10 years’ time to twenty years. As such, the moon cactus is completely different when compared with the rest of the cactus.

Although they live for shorter periods, so many people love to grow these cacti due to the unique beauty.

Moon Cactus Size

How to care for moon cactus to their maximum size


Moon cactus would require only a minimal watering.  They do not expect you to water them on a frequent basis.

On another note, moon cactus would thrive well when they get rainfall. If you are someone who lives in an area where you get frequent rainfall, best is to grow them in a covered porch if you have grown them outdoors.

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If you are clueless whether you need to water the moon cactus or not, you could check the soil condition and feel whether it is too dry or whether it is soggy.

If you feel like the soil is dirt and dusty, you could consider watering them mildly. Do not over water them though.

If you provide too much water, it will make the potting medium waterlogged and soggy . Not only that but also, it would make the potting soil run over from the pot ends as well. 

Be mindful to not over water the moon cactus as it would badly affect the cactus.

Furthermore, it is best to avoid watering the older moon cactus which are one year old and above, particularly in seasons like winter. 

On the other hand, if you have some young moon cactus, you could water them lightly. 


You need to  provide indirect and bright sunlight for the moon cactus to grow well.

However, the upper part of the grafted moon cactus could survive in shade as they are not fond of direct sunlight.

Further, the green stem of the cactus needs some direct sunlight so that they can thrive well. So, when considering the above, it is important that you provide the right amount of balanced sunlight which could consequently help the plant to stay vigorous and stay healthy.

In terms of providing sunlight for indoor grown moon cactus, you need to locate them near a bright and sunny spot.

So, it could possibly be somewhere closer to a bright sunny window. It would make sure that the plant gets adequate balanced sunlight.

Avoid exposing the plants to intense sunlight as that would cause plant burns. 

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In terms of fertilizing the moon cactus, they do not require it on a frequent basis. However what is important is to provide a potting medium which has essential nutrients.

However, best is to feed the moon cactus once a month in summer and in spring. When you feed them during their growing season, the growth of the cactus would be benefited from that.

When feeding, best is to use an organic based cactus fertilizer. However, always make sure that you follow the guidelines on the label.

You should flush the soil once you apply fertilizers as that would help to avoid any potential mineral build of the soil. 

If you do not flush the soil, it would cause stunt growth of the cactus.

Moreover, refrain from over feeding the moon cactus, because it would deteriorate the overall health of the cactus and will further end up in making the cactus turn yellow.

Moreover refrain from applying fertilizers for the moon cactus during winter as well as in fall too.

Moon Cactus Size


In terms of providing a right soil mix for the moon cactus, you need to make sure that your soil mix has a better aeration as well as a fast-draining feature too.

I would recommend using a sandy soil mix as that would allow the excess water to drain through the draining holes.  

Instead of using a sandy soil mix you may also consider adding substances such as pebbles, small tones in a regular soil mix  and growing them there.

Once you add these substances that would fasten the drainage of the regular soil mix. That would greatly fit the moon cactus to grow well. when it comes to the ph. of the soil mix, it ideally has to be either acidic or neutral.


If you consider the temperature for these cacti to grow well, they would mainly like to stay in warmer temperatures.

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Room temperature would suit them the best. Do not let the moon cactus to gain intense heat since that would badly affect the cactus.

If you live in USDA hardiness zone 10 and 11 you could grow this as an outdoor plant. You only need to make sure that you grow them at a bright sunny spot outdoors where they will be partial shade available as well.

On the other hand, if you live in temperate climates, you could shift these cacti outdoors when the temperature increases. 

Further when the temperature reduces at nighttime, you could bring them indoors.

When you grow them as houseplant, do not grow them closer to colder grafts such as open windows, air conditioners.

Further, do not grow them in intensely heated places as well. Moon cactus are not tolerant of temperatures which are below 48 degrees Fahrenheit. (9 degrees Celsius)

Related question 

Can moon cactus grow without grafting?

Moon cactus cannot grow without grafting as they can’t grow on their own. They want to have chlorophyll which in return would be helpful for the photosynthesis process of those plants.

Unfortunately they do not have it and hence why you need to graft them with a host plant and make them thrive well.

Can moon cactus be planted outside?

You could grow them outside if you live in a warm environment. Make sure the temperature there does not drop below 60 degrees Fahrenheit.

You could let them grow outdoors especially during the warmer seasons. However, you need to bring them indoors when the  temperature decreases, especially at nighttime.  

It would be quite fatal if you expose the moon cactus to frost.

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About author

I’m Dr. Chamika, As a hobby love talking about plants and showing you that taking care of indoor plants. My website is knowledge I’ve learned over the years and continue to learn about growing succulents. If you’re a succulent lover, then you have come to the correct place.