Why is My Cactus Dying

Although caring after a plant can be quite therapeutic, it can also get very frustrating if you are unable to keep your plant alive. This is why we encourage all inexperienced plant parents to first start with a cactus before bringing home a sensitive plant species.

Cactuses are excellent indoor and outdoor plants that thrive in deprivation and can survive in unideal living conditions for long periods.

However, if the plant parent continues to practice the incorrect care routine on their growing cactuses, the plant eventually begins to lose color, thorns, and healthy before dying prematurely.

Keep reading below to learn in detail about what may be causing your potted or planted cacti to die prematurely.

What Makes a Cactus So Tolerant?

If you have ever owned or seen a cactus, you already know that this dessert plant looks nothing like the other indoor planters or succulents you have.

While most plants are characterized by the size of their stems or the shape and color of their leaves, one cannot do the same for a cactus.

Instead, cactuses are known and desired for their unique thorny appearance and thick trunks. Although these unique physical attributes add to a cacti’s appeal, this is not all that they do.

By not having any leaves like regular plants, cactuses are able to minimize their water loss through transpiration or diffusion.

Moreover, while other plants have thin stems that help transport food and water, the cactus has a thick trunk that is able to store a reserve of water for a long period.

As a result, the cactus is able to retain its hydration, photosynthesize food, and survive even when it is exposed to unideal living conditions.

Why is My Cactus Plant Dying?

Cactuses are one of the very few plants that can grow both indoors and outdoors and can stay alive for multiple decades. As a matter of fact, cactuses that grow in the wild are able to live up to even a century!

However, although a cactus plant’s resistance and endurance are truly remarkable, prolonged periods of neglect and poor care will eventually lead to the dessert plant’s premature death.

Some of the most common reasons for a healthy cactus plant’s early death are as follows:


Unlike most other outdoor plants, a cactus thrives in drought-like living conditions. Since it is able to store a good amount of moisture in its trunk, it does not dehydrate too easily. The goal is to water a growing cactus only when its soil is fully dried-up.

However, if the plant parent continues to frequently overwater their cactus plant, they will end up creating a muddy medium that attracts fungal growth.

If nothing is done to kill the fungus on time, it will grow all the way to the cactus’ roots, causing them to decay and die. This disease is called root rot.

Although the cactus is able to survive on its stored water for an impressive period, it will however eventually require more water. If a majority of its roots are dead, the entire plant will be deprived of water, and will thus dehydrate.

Moreover, since water is a key ingredient in the photosynthesis process, its lack thereof will directly affect the dessert plant’s ability to produce its own food.

If such conditions continue for long enough, the shortage of water and plant sucrose will eventually cause the cactus’ death.

Lack of Sufficient Sunlight

Cactuses are one of the very few plant species that have the ability to grow up to incredible heights and sizes. While some species of cactuses are known for having a 15 to 16 feet height, there are others that can nearly grow up to 45 feet tall!

Hence, a cactus is highly dependent on its self-produced plant food for its energy and nourishment. While water is a key ingredient in the photosynthesis process, sunlight is the sole catalyst for the reaction.

If the growing cactus plant is deprived of sufficient sunlight exposure, its ability to produce sucrose will take a toll, and the plant’s growth rate will drop. Eventually, deprivation will lead the cactus to its death.

Excess Atmospheric Humidity

At times plant parents that water their cactuses less frequently still end up killing their plant. The reason behind this usually is high atmospheric humidity.

While people are able to monitor their watering routine, they usually do not know how dangerous high humidity can be.

Since the moisture in the air will keep the cactus’ soil wet at all times, the chances of root rot and premature plant death can go up.

Low External Temperatures

Cactuses are dessert plants that grow best in hot and dry weather. Although they are able to survive a drop in temperature, their growth however considerably slows down during prolonged and harsh winters.

Moreover, since low temperatures can cause moisture in the soil to freeze up, the soil never gets to dry out fully. As a result, fungus growth might occur and the plant may die from poor growth and root rot.

Poor Ventilation

Even if the atmospheric humidity levels are not too high, poor ventilation can create a big problem for cactuses that are grown indoors.

As a result, the accumulated humidity will keep the cactus’ soil wet, causing it to die from root rot.

Low-Quality Potting Mix

Moreover, just like the amount of water and intensity of light, the quality of the potting mix will also play a major role in the cactus plant’s ability to survive.

Ideally, a cactus’ soil needs to be well-draining, sufficiently aerated, and highly nutritious. If the soil being used lacks these qualities, the cactus will have a poor growth rate and will not develop enough immunity during its lifetime.

As a result, any minor disease, infection, or infestation may cause the cactus to die.

Correct pot Type

Finally, the type of pot being used to grow the cactus can also impact its expected lifespan.

As mentioned above, cactuses need dry soils that have very little moisture. If the pot being used either has a non-absorbent inner surface or lacks sufficient drainage holes, even a little water might accumulate inside the dessert plant’s soil.

As a result, the roots might rot and die from a fungal infection, which can cause the entire cactus plant to die from dehydration and lack of sufficient plant food.

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Final Thoughts

Although a cactus can endure unideal living conditions, prolonged overwatering, excessive humidity, and lack of sufficient light can cause it to die prematurely. Hence, ensure to check the moisture level of the soil before adding any more water to it, and invest in an infrared lamp if sunlight hours are enough.