Why Is My Cactus Turning White? – 12 Causes And Solutions

Why Is My Cactus Turning White

Cacti are beloved for their unique and resilient nature, making them popular for indoor and outdoor plant enthusiasts. However, one common issue many cactus owners encounter is their plants mysteriously turning white. This puzzling phenomenon can be alarming and confusing.

Your cactus might turn white for various reasons, such as sunburn, powdery mildew, or pests. Sunburn occurs when the cactus is exposed to excessive sunlight, while powdery mildew is a fungal infection causing white spots. Pests like mealybugs can also make the cactus appear white.

To know more, you can explore some causes for a cactus turning white in this article. I’ll also provide practical solutions to help you revive your plant.

Common Causes of Cactus Turns to White

If you’ve noticed your cactus displaying a peculiar white discoloration, fret not – it’s a common phenomenon with various underlying causes. Understanding these factors is pivotal in returning your cacti to their vibrant, green glory.

Here’s a breakdown of the typical culprits behind the enigmatic phenomenon of white cactus:


Excessive exposure to direct sunlight can scorch the delicate skin of cacti, leaving them with unsightly white patches. Just like humans, cacti need their sun in moderation.

Powdery Mildew

A fungal infection, powdery mildew, manifests as a white, powdery substance on the cactus’s surface. It mars the aesthetic and hampers the plant’s ability to thrive.


These tiny, white insects are notorious for infesting cacti. Their feeding habits drain the plant of essential nutrients and cause the affected areas to turn white and lose vitality.

Low Soil Moisture

Insufficient water in the soil can lead to dehydration, causing cacti to lose their natural green hue and appear pale.

Improper Watering

Overwatering or underwatering your cactus can disturb the delicate moisture balance, leading to white patches. Finding the right watering rhythm is essential for their well-being.

Fungal or Bacterial Infections

Various fungi and bacteria can attack cacti, causing them to develop white lesions or spots. Proper hygiene and care are crucial in preventing these infections.

Nutrient Deficiencies

Lack of essential nutrients, particularly nitrogen, can result in pale or white cactus parts. A balanced fertilizer regimen is vital to combating this issue.

Mineral Deposits or Hard Water Stains

Minerals in hard water can accumulate on the cactus’s surface, creating a white film. Regular cleaning and using filtered water can mitigate this problem.

Natural Aging or Scarring

As cacti age, they may develop white spots or scars naturally. While these blemishes are a testament to the plant’s longevity, they can sometimes be mistaken for issues requiring attention.

Environmental Stress

Cacti are sensitive to abrupt environmental changes. Exposure to extreme temperatures, drafts, or sudden shifts in light can stress the plant, leading to white patches.


Excessive fertilization can disrupt the nutrient balance, causing the cactus to turn white. Following recommended fertilization guidelines are vital for their overall health.

Pests and Diseases

Various pests, such as spider mites and scale insects, can infest cacti, leading to discoloration. Regular inspection and prompt treatment are essential in preventing infestations.

Signs and Symptoms of a White Cactus

The color change and various symptoms may sometimes hint towards disease, dehydration, sun damage, or over-watering factors. Here are a few signs and symptoms to look out for in a white cactus.

Color Change

If your cactus is turning white, it could be due to a change in its environment. It might be receiving too much sunlight or not getting enough. A layer of cork causes the whiteness that the cactus produces to protect itself from the sun.

White Fuzz/Cottony Substance

A common symptom of mealybugs or scale, pests that cacti can suffer from. These insects look like little cottony masses and can hinder nutrient absorption, causing slow growth.

White Mold

White mold or powdery mildew is another symptom, and it’s a fungal disease. If you notice a white, powdery substance on your cactus, it’s likely this.

Spots or Patches

White spots or pale patches might indicate sunburn. Despite being desert plants, Cacti can still get sunburned if exposed to direct sunlight for extended periods. These areas may appear sunburned, bleached, or discolored.

Dying or Dead Spikes

If the cacti spikes start to die or turn white, it could be because the cactus is suffering from pest damage or a nutrient deficiency.

Pediatric Translucence

This is where the skin of the cactus becomes thin and translucent, showing the inner fibrous material. It can be caused by various issues, including too little light, over-watering, under-watering, and temperature fluctuations.

Soft or Mushy Tissue

Affected areas of the cactus may become soft or mushy to the touch. This can be a result of sunburn, rot, or other forms of damage.


In addition to turning white, cacti can develop yellow or light-colored patches. This often occurs when the cactus is exposed to excessive sunlight or if there’s an underlying issue like fungal infection.

Wrinkling or Shrinking

The cactus may start to wrinkle or shrink, especially in the affected areas. This is a sign of dehydration and stress.

Stunted Growth

A cactus turning white and experiencing stress may exhibit stunted growth. It may stop growing or show signs of weakness.

Brown or Black Spots

If the white patches have been damaged further, they may develop into brown or black spots, indicating tissue damage or decay.

Visible Pests

Inspect the cactus closely for visible pests such as mealybugs, scale insects, or aphids, which can leave behind white or waxy secretions.

Discolored or Unhealthy Areoles

Areoles are the small, round, or oval structures on a cactus from which spines and flowers grow. If the areoles are turning white or discolored, it can be a sign of an issue.

Unusual Growth Patterns

Sometimes, a cactus may respond to stress by developing unusual growth patterns, such as odd-shaped or elongated segments.

Fungal Growth

In cases of fungal infection, you may notice fuzzy, white, or mold-like growth on the cactus’s surface.

Cactus Leaning or Tilting

Severe stress or damage can cause the cactus to lean or tilt to one side as it struggles to maintain its balance.

Diagnosing the Main Cause of Cactus Turning White

Diagnosing the cause of a cactus turning white involves careful observation and consideration of various factors. Here are the steps to help you identify what might be causing your cactus to turn white:

Visual Inspection

Examine the cactus closely to get a clear understanding of its condition. Look for any signs of discoloration, damage, or abnormalities on the cactus’s surface.

Check Sunlight Exposure

Consider the cactus’s recent exposure to sunlight. If the white areas are primarily on one side of the cactus that faces the sun, sunburn may be the likely cause. If you’ve recently moved the cactus to a new location with different light conditions, this is an important clue.

Examine Watering Habits

Evaluate your watering practices. Overwatering can lead to root rot and subsequent white discoloration. Underwatering, on the other hand, can cause stress and may result in white or yellow patches.

Inspect for Pests

Thoroughly check the cactus for pests like mealybugs, scale insects, aphids, or spider mites. These pests can leave behind white, cottony, or waxy secretions.

Look for Signs of Disease

Examine the cactus for any signs of fungal or bacterial infection. This may include fuzzy or mold-like growth on the surface or black or brown spots.

Consider Environmental Factors

Review the cactus’s overall environment. Extreme temperatures, frost damage, or exposure to harsh weather conditions can cause stress and lead to white discoloration.

Check Soil and Drainage

Evaluate the soil in which the cactus is planted. Poor drainage or using the wrong type of soil can contribute to root problems and stress. Ensure that the pot has drainage holes.

Age and Natural Variations

Some cacti naturally have white or lighter-colored areas as part of their genetic makeup or as they age. Research the specific cactus species to determine if this is normal.

Previous Actions

Think about any recent changes or actions you’ve taken with the cactus. Have you recently repotted, pruned, or introduced it to a new environment? These actions may have caused stress.

Ask for Expert Advice

If you need clarification on the cause, consider seeking advice from a local nursery or cactus expert. They may be able to provide valuable insights based on their experience.

How to Treat and Revive a White Cactus?

Reviving a white cactus demands a strategic approach that addresses its specific needs. Here’s a step-by-step guide to nurse your pale succulent back to vibrant health:

Optimal Sun Exposure

Ensure your cactus receives the right amount of sunlight. Adjust its placement to provide adequate but not excessive sunlight, shielding it from harsh midday rays.

Relocate the Cactus to an Ideal Environment

If your cactus has suffered from sunburn, move it to a location with filtered sunlight or partial shade. This relocation can prevent further damage and aid in recovery.

Adjusting Watering Schedule

Evaluate your watering routine. Cacti prefer infrequent, deep watering. Adjust the schedule to maintain the soil’s moisture balance, preventing underwater and overwatering.

Treating Fungal Infections

If your cactus is afflicted with powdery mildew or any fungal infection, treat it with appropriate fungicides. Follow the instructions carefully to ensure effective eradication.

Proper Fertilizing

Provide your cactus with balanced, diluted fertilizer. Avoid over-fertilization, as it can stress the plant. Follow recommended guidelines and monitor the plant’s response.

Pest Control

Implement pest control measures if mealybugs or other insects are the culprits behind the white patches. Natural remedies or insecticidal soaps can be effective, but consistent monitoring is crucial.

Choose a Suitable Pot

Assess the pot your cactus resides in. Ensure it has drainage holes to prevent waterlogging. Consider a pot made of breathable materials like terracotta, allowing excess moisture to escape.

Repot Using Ideal Potting Mix

If the current potting mix is too dense or water-retentive, repot your cactus using well-draining soil formulated explicitly for cacti. This promotes aeration and prevents water accumulation.

Prune Damaged Parts

Carefully trim any white or damaged parts using sterilized tools. Removing affected areas can stimulate new growth and prevent the spread of infections.

Monitor and Adjust

Regularly monitor your cactus’s progress. Be patient; recovery takes time. Observe new growth and adjust your care techniques based on the plant’s response.

Preventing Cactus from Turning White    

Preventing a cactus from turning white, typically due to sunburn or other stress factors, involves providing proper care and protection to ensure its health and well-being.

Here are some steps to help you prevent your cactus from turning white:

Prevent Sunburns

Even though cacti are desert plants, they can still suffer from sunburn if they are suddenly exposed to intense sunlight.

Gradually increase the amount of sunlight your cactus receives, especially if it’s a new plant or if you’re moving it to an area with more sun exposure. Use a shade cloth if the sunlight is too intense, particularly during the day’s hottest hours.

Avoid Over-watering

Over-watering is a typical issue when caring for cacti. Too much water can cause root rot, making the cactus turn white. Ensure your plant has excellent drainage and you’re watering it correctly. As a rule of thumb, only water a cactus when the top inch of soil is completely dry.

Regular Pest Control

Pests like mealybugs or scale insects can also cause whiteness in a cactus. These critters suck on the cactus’ tissues, leading to discoloration. Prevent pests by regularly inspecting your plant and treating it with natural or chemical insecticides if you notice any infestations.

Fungal Prevention

Excessive moisture or poor air circulation can lead to fungal disease. Avoid over-watering and ensure your cactus is in a well-ventilated area. If you suspect a fungal infection, you may need to treat the plant with a suitable fungicide or, in severe cases, remove and dispose of the affected parts.

Use Good Soil

The right sort of soil can protect a cactus from many problems. Use a well-draining cactus or succulent mix, ensuring enough grit or sand to prevent waterlogging.

Good Hygiene Practice

Always make sure your tools (like pruners, shears, etc.) are clean before using them on your cactus to prevent the spread of disease. Maintaining a good environment, providing proper care, and periodic inspection can help prevent your cactus from turning white.

Final Words

A white cactus may signify stress or damage, sunburn, pests, or disease. You need to assess your cactus’s environmental conditions and care routine to determine the cause of the discoloration. Your cactus can recover and thrive with proper care and attention.

If you are still concerned, consult a professional or further research to ensure your cactus stays healthy and vibrant. Remember, every cactus is unique and may require different care, so stay attentive and adjust accordingly for a happy and healthy plant.


  • https://www.quora.com/Why-is-my-cactus-turning-white
  • http://www.cactusedintorni.com/en/The-diseases/index.html 

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