Do Moon Cacti Need Sunlight? (With Table and Infographics)

Do Moon Cacti Need Sunlight?

All living animals and plants need sunlight, whether it is big or small. If you have houseplant moon cacti, they need bright indirect balance sunlight.

Unlike other robust and resistant cacti,  moon cacti are much more delicate, soft, and aesthetic. They can’t sustain themselves and even do not like intense direct sunlight. Moon cactus prefer bright indirect sunlight for 4 to 6 hours, especially in the morning and in the evening hours.

What is A Moon Cactus?

The Latin designation is Gymnocalycium mihanovichii.  It has a variety of common names, like ruby ball cactus, and Hibotan. The moon cactus is a mutant, lacking the chlorophyll that is required to enable plants to survive by the process of photosynthesis or turning light into a life force.

Consequently, this species is usually grafted onto another variety of cactus.  And its bright color makes it a popular ornamental plant, although it has a relatively short lifespan for a cactus.

This is the case with moon cactus seedlings. Cactus seedlings can only survive for a few weeks without sufficient chlorophyll. They will die if there is not enough chlorophyll to convert sunlight into food.

If, however, Gymnocalycium mihanovichii is transplanted onto a succulent with chlorophyll such as Hylocereus Species (the Rootstock), it may last for years.

Depending on the type of base cactus chosen, a moon cactus never exceed 12 inches (30.5 cm). Although a variety of cacti can last for some years,  the Hibotan is a comparatively small time span. The most base cactus will not keep the whole plant alive over a couple of years.

Why Do Plants Need Light?

Light is the source of energy that plants require to produce the food they need to grow and blossom. Plants are the only living organism capable of using light energy to make sugars along with starches, and other ingredients required by them and from other living creatures.

As described in the University of Minnesota Extension website Light is one of the most important factors for growing houseplants. 

Moon Cactus Love  Shady Sunlight (Under Tree)

cactus under a shady tree or behind a window

Moon cacti must have a lot of indirect sunlight, and grafted cacti must-have shade in order to thrive.

Due to the different light preferences of the two parts of the moon cactus, it is necessary to ensure both parts of the plant receive a balanced amount of sunlight. Place the moon cactus in a bright shade where it can receive 4-6 hours of indirect, slanted sunlight daily.

By doing so, the scion will not burn, and the rootstock will also be able to absorb enough light. Remember to pick a spot that is ideal for both parts of your moon cactus, as well as perfect for its growth.

Ideal Indoor Location For Moon Cactus (Windowsill?)

As described in the Austin Gardening website Your Moon Cactus will thrive on your windowsill… as well as on the porch or patio. Its environment is pretty flexible since it only requires filtered light or shade with a good flow of air.

The best location for your moon cactus is near a south-facing or east-facing window sill in your home or office.

This means the moon cactus can absorb at least two hours of morning or afternoon sun and four hours of bright light for the rest of the day to undergo photosynthesis.

A Table of Moon Cacti, Desert Cacti, and Tropical Cacti Differences

SunlightHours Of LightIndoorsTemperatureHumidityLess Light Excess Light
Moon CactusBright indirect sunlight4-6 hours dailyA window sill is ideal 18-25°CLove moderate humidityEtiolation, Paleness, rot rootSunburn, Discoloration, wrinkled
RootstockBalance Direct sunlight14 hours daily (max.)windowsillCan tolerate intense temp.Love more humidityEtiolation, Paleness, rot rootSunburn, Discoloration, wrinkled
Desert cactiDirect sunlightWhole daynaturescorching sunLess humidity situationNot Etiolation, Paleness,  and rot rootNo Sunburn and Discolor
Tropical cactiIndirect sunlight12 hours dailyIndoors or outdoors18-25°CLove moderate humidityEtiolation, Paleness, rot rootSunburn, Discoloration, wrinkled

How Much Sunlight Do Moon Cactus Need?

sunlight for moon cactus

They do not like to get exposed to direct sunlight. However, green stems would enjoy growing in direct sunlight because it helps them produce food through photosynthesis.

In such a case, you need to provide balanced light so that the plants could thrive well. This means that you can’t place the cactus in an area that is constantly bright. If you have a bright room, you might want to place the cactus near a window so it can get some natural brightest light. 

If you see your moon cactus starting to turn white or develop scars, you need to move it to a shady place right away.

Prolonged exposure to the sun can cause the plant to die. Moon cacti prefer bright, indirect light and should not be placed in direct sunlight.

How Many Hours Of Light Does A Cactus Need?

Cacti that grow in direct sunlight would require 12 hours of sunlight per day. Moon cacti, however, need indirect daylight for one to two hours in the morning or afternoon, either in a shady area that’s still bright or near a window that’s always bright.

It is advisable not to expose the moon cactus to light for longer than 14 hours each day.

It’s essential that your rootstock cactus receive enough sunlight for photosynthesis. Place it near a window, but only allow partial sunlight to reach the rootstock since direct sunlight can damage it. 

Desert cacti can tolerate direct sunlight, while tropical cacti would prefer indirect sunlight.

As a rule, cacti are not tolerant of direct sunlight, and they are not immune to sunburn.

Moon Cactus Survive in Indoors

Your cactus could be subjected to intense and heated sunrays, which could cause severe sunburns in someone using the glasses behind them. It could create a highly heated gradient behind the glasses, whereas the room temperature could be much lower.

Further, if you have a balcony at your house, you may keep them there actus can survive indoors. As aforesaid, the ideal place to locate the moon cactus would be on a windowsill.

Can Moon Cactus grow under Artificial Lights?

artificial light

Lack of adequate light is the most common factor limiting the growth of plants in many areas of the home. Supplementary electric lighting is usually the easiest and least expensive way to provide enough light for plants that do not receive adequate natural light.

You could consider providing artificial light if it is not possible for you to provide natural sunlight for the moon cactus. Pick bulbs with little light and no heat if you are using bulbs.

For the best moon cactus growing, you can buy fluorescent bulbs or fluorescent tubes from

It is also possible to use LED grow lights instead of mercury vapor or incandescent bulbs.

Temperature Needed for Moon Cactus

temperature checker for moon cacti

Warm summer temperatures are ideal for the moon cactus. An average room temperature would be best.

Moon cactus grows well in warmer temperatures with bright indirect sunlight.

Temperatures between 64° and 77° Fahrenheit are optimal for cactus growth. 

In the winter, they prefer temperatures between 50° and 60° Fahrenheit.

If it begins to fall, you could bring the plants inside when the temperature decreases. However, do not place them close to drafts such as open windows or air conditioners.

Colder than 48 degrees Fahrenheit is too cold for moon cacti, cannot withstand.

What Is the Ideal Humidity for the Moon Cactus?

Ruby ball cactus plants have pretty straightforward needs for moisture. They thrive in relative humidity.

In low humidity levels, they can also survive. The most crucial care tip is to make sure the soil is always dry before adding moisture.

You can mist pink, red, orange, or yellow cacti occasionally to keep their canopies vibrant and healthy. This provides the necessary moisture without wetting the soil.

In the winter, you should maintain high humidity levels by misting the cactus. In October and February, do not water the moon cactus.

How to Check Light Deficiency in Moon Cactus?

Plants that aren’t getting enough light could lose their leaves, particularly the older leaves. Lack of light results in the growth of longer spaces on stems, which are located between leaf nodes (the point where the leaf emerges from on the stem).

Etiolation/ Stretching


Etiolation is a condition caused by plants and caused by poor light. The plants have tiny yellow leaves, and long internodes that occur in the case of moon-cactus, which are desperate to find light sources. It extends from the point that is growing in its center.

Poor light can result in etiolated growth, especially on cactuses. Etiolation is a process that

occurs with plants grown in insufficient light.

“Keeping a moon cactus in a spot with little to no light will result in etiolation.”


Etiolation is typically followed by a pale appearance. When the moon-cactus does not absorb enough sunlight, photosynthesis is not able to function. The plant will not produce enough food to feed its system Therefore, the growth is of poor color.

Your moon cactus will get its vibrant color back if you move it gradually into a bright, shaded area.

Root Rot

As mentioned on the Austin gardening website that doesn’t overwater your plant. This cactus does not need a lot of attention so excessive watering will cause the roots to begin to rot.

Also, never let the plants sit in water.  This is kind of the same thing as overwatering and can lead to rotting.

How to Check Excess Light in Moon Cactus?



Sunburnt moon cactus forms dark brown spots on the epidermis. The patches appear calloused and rough.

The harm caused by sunburn is irreparable. If you see this sign or symptoms,  relocate your moon cactus immediately to a shade so that it will be exposed to indirect light.

Plants exposed to too much light may result in scorched and bleached leaves.


Moon cactus that is exposed to too much sunlight will alter its color. While it may appear vibrant and joyful it can begin to look dull and bleached. The intense light that comes from solar radiation causes the color to change.

Sometimes, the moon cactus rootstock can change color from brown to yellow.


Exposure to the sun for long periods of time will cause the moon cactus’s skin to become wrinkled from the outside. It is usually due to being burned.

Related Questions

Is Light Color Important to Plants?

Certain colors of light have been proven to be more crucial to plant growth than other colors. Leaves reflect light and get very little energy from green and yellow wavelengths of the spectrum of visible light.

However, the blue and red wavelengths of the spectrum of light are the main plant energy sources.

The plants that grow outdoors in greenhouses, outdoors, or near window frames are exposed to a variety of different wavelengths of light from the sun, which includes the red and blue sunlight that plants need.

What Window Provides the Best Light?

When selecting windows to plant plants in, think about the dimensions, direction, overhang, and shade from buildings or trees.

Large windows create the best conditions for growth and permit plants to be placed quite far back in a room. Even low-light plants don’t get enough light in distances of more than 10 feet away from a typical window. The most suitable glass windows to plant in are not shaded by an overhang, trees, or any other structures.

South-facing windows provide the most bright light conditions and last for the longest time. In winter, every houseplant gets the benefit of light from windows facing south. South windows are ideal for plants that need sunlight and bright sunlight.

Key Takeaways

  1. Moon cactus love bright indirect sunlight, but its host lives on balance direct sunlight.
  2. Too much heat or less heat both are harmful to moon cacti. Extremities are the game looser of the ruby ball. 
  3. Temperatures between 64° and 77° Fahrenheit are ideal for your loveliest cacti.
  4. Daily 4-6 hours moderate sunburn is the great healer for your Hibotan.

Anwar Hossain

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

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