Why Is My Cactus Turning White | 7 Reasons and Solutions

If you wonder, ‘Why Is My Cactus Turning White?’, discover what’s behind your plant losing its vibrant hue!

If you’re muddling about, Why Is My Cactus Turning White, you’re not alone. Many cactus owners find themselves puzzled by this unexpected transformation. This informative guide explores the underlying causes and actionable steps to bring your cactus back to life. Read on to discover secret tips to keep your desert gem healthy and thriving!

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Is it Normal for a Cactus to Turn White?


A cactus turning white is technically not normal as it could be indicate various underlying issues requiring immediate attention. It could be due to sunburn, fungal infection, or simply a pest infestation, which manifests as white or bleached spots on the skin of the cactus.

Regardless of the cause, a cactus turning white is a warning signal that the plant’s health is compromised and requires immediate care to inhibit any long-term deterioration to plant health.

Why Is My Cactus Turning White?

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A cactus turning white could be troublesome; however, addressing the exact reason will help you find the possible solutions to its healthy growth.

1. Over Sun Exposure

When your cactus gets too much sun, it’s not soaking up rays; it’s getting scorched. A cactus is exposed to intense, direct sunlight for extended periods can get sunburned, leading to a whitening of the plant. This condition is irreversible and may weaken the cactus, making it further susceptible to other diseases.

How to Identify?

Look for white or bleached spots on the areas most exposed to direct sunlight.


  • If you’re moving your cactus to a sunnier spot, do it gradually. Start with a few hours of sunlight and slowly increase it over time.
  • During the hottest part of the day, move it to an area that receives filtered sunlight through a curtain, or use a shade cloth with 30-50% shading capacity.

2. Over-Feeding

When we talk about overfeeding a cactus, we’re referring to giving it too many nutrients or fertilizers, which can cause root burn and nutrient imbalances. This manifests as a whitish discoloration on the cactus skin, especially near the base.

How to Identify?

Observe whitish discoloration near the base of the plant and check for salt buildup on the soil’s surface.


  • Leach the soil by running distilled water through it until the water drains freely.
  • Afterward, switch to a balanced, slow-release fertilizer like a 10-10-10 (N-P-K) but use it at half the recommended dosage.

3. Poor Ventilation

Lack of air circulation can cause humidity to build up, creating a favorable environment for fungal growth, leading to white mold or spots on the cactus. Poor air movement hinders the cactus’s ability to transpire, affecting its overall health and possibly causing whitening.

How to Identify?

Check for a white, powdery substance on the cactus surface, often accompanied by a musty odor.


  • Install a small oscillating fan near the plant to improve air circulation.
  • If the condition persists, apply a sulfur-based fungicide, following the manufacturer’s guidelines for application rates and timing.

4. Imbalanced Watering

Watering imbalances can lead to various physiological issues. Overwatering usually results in root rot, which can cause the plant to lose its vibrant green color, turning it a pale or whitish hue. On the other hand, underwatering stresses the plant and leads to a faded, whitish appearance, particularly on the tips and ridges.

How to Identify?

Examine for a pale or faded appearance and check the soil for either excessive moisture (overwatering) or dryness (underwatering).


  • Establish a watering schedule based on the cactus species—for a desert cacti, allow the top 1-2 inches of soil to dry out before watering. For forest cacti, keep the soil slightly moist but never waterlogged.

5. Inadequate Temperature

Just like we need the right temperature to feel comfortable, cacti require a proper balance of heat to thrive. Extreme temperatures leads to significant stress in cacti. Cold temperatures can induce a state of shock in the plant, leading to a whitening or yellowing of the skin. Conversely, heat stress might lead to localized sunburn, further causing white or bleached patches on the plant.

How to Identify?

Notice a sudden whitening or yellowing after a dramatic temperature change, either too hot or too cold.


  • Most cacti prefer temperatures between 60-90°F (15-32°C). During winter, a cooler period of 50-55°F (10-13°C) is fine for many species. Try not to fluctuate the temperature levels beyond this range.
  • If your cactus is in a pot, move it indoors during extreme temperatures.

6. Nutrient Deficiency or Imbalance

A deficiency in essential nutrients like nitrogen, potassium, or phosphorus can lead to discoloration in cacti. The plant’s inability to produce sufficient chlorophyll due to nutrient imbalance can manifest as a pale or white appearance, signaling disrupted metabolic functions.

How to Identify?

Look for an overall pale appearance and check for older leaves turning white before younger ones.


  • Use a soil test kit to determine nutrient levels. If deficiencies are found, use a balanced, slow-release fertilizer with micronutrients.
  • You may also use a foliar spray with the lacking nutrient for severe deficiencies.

7. Pest Infestation

Pests can wreak havoc on your cactus’s health. Pests like mealybugs and spider mites pose a significant threat to cacti. These pests often produce a waxy, white substance or webbing that envelops the plant. This covering not only affects the appearance but also inhibits photosynthesis by blocking light, further compromising the health of the cactus.

Larvae of cactus moths or Cactoblastis can damage the plant badly. They burrow into the skin of the cactus, feeding on its tissues, leading to its whitening.

How to Identify?

Identify a waxy, white substance or fine webbing on the plant, often accompanied by visible pests.


  • Target the infected spots with a strong water jet and treat your cactus without the use of any chemical. This is suitable in cases of low pest infestation.
  • Use a cotton swab soaked in a 70% isopropyl alcohol solution to remove visible pests. For persistent infestations, apply an insecticide like neem oil, making sure to cover all plant surfaces. However, be careful with the spikes.

Final Words

In conclusion, if you’ve been wondering why your cactus is turning white, it’s essential to understand that this transformation can be caused by various factors, as we have already discussed. By addressing the root cause and providing the necessary care, you can help your cactus regain its vibrant green color and grow healthily. Whether it’s adjusting the watering schedule, modifying the nutrient balance, or optimizing light exposure, taking prompt action is key to your cactus’s well-being.

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