Why Is My Cactus Turning Light Green?

Cacti are hardy houseplants that are popular for their exotic appearance and minimal maintenance needs. Sometimes, the cactus tends to start discoloring into a pale green appearance . It signifies an unhealthy cactus that is undergoing severe stress. You should take preventive steps to ensure that the plant recovers its health and regains its original color.

Why Is My Cactus Turning Light Green?

The following are some of the common reasons which lead to the discoloration of the cactus-

  • Inappropriate Sun Light
  • Improper Watering
  • Nutrient Deficiency
  • Pest Infestation

1. Inappropriate Sun Light

If the cactus grows taller than it is supposed to and the new growth is pale green, it means the plant is not getting adequate sunlight. The plant is only trying to adapt and reach a height where it gets the required sunlight.

Similarly, if the cactus is exposed to too much direct sunlight, it causes sunburn. The outer layer gets bleached and discolored to light green or yellow.


The ideal solution is to allow a balanced amount of sunlight. A cactus needs around 6 hours of bright, indirect sunlight each day. So, to ensure that the plant becomes healthy again, place it in an area of partial shade where it gets adequate indirect, bright light.

2. Improper Watering

If the cactus is overwatered, its stem turns mushy and soft. It can also give rise to rotting in the cactus, which causes discoloration in the outer layer of the cactus to and it turns light green.

Similarly, under watering the cactus may cause dehydration, and eventually, the plant turns light green.


Check the over-watered cactus for root infections like root rot. If infected, cut off the sick roots and treat the plant with an effective fungicide. The plant should then be re-potted in fresh, sterile soil in a pot with proper drainage.

Adequately water an underwater cactus in regular intervals until the plant is re-hydrated and the original color returns.

3. Nutrient Deficiency

Cactus needs essential macro-nutrients like nitrogen, magnesium, and phosphorous to survive. If the required minerals are deficient, the cactus weakens and the skin of the cactus turns light green.

It generally happens when there is rotting in the roots and the roots are unable to absorb the required minerals. Similarly, if the soil on which the cactus is planted is not mineral enriched, the cactus tends to discolor.


If the roots of the cactus are rotting, the best way is to trim the affected roots and treat the plant with an effective fungicide. However, if the soil is nutrient deficient, you should re-pot the cactus with fresh, fertile soil. It should be supplemented with nutrient-enriched fertilizer in regular intervals until the cactus regains its original color.

4. Pest Infestation

Pests such as scales, red spiders, and mealybugs cause severe damage to the cactus by sucking out the plant sap. It causes the plant to weaken and discolor, making the cactus appear light green.


Immediately isolate the infested plant to stop the further spread of the pests. Spray an effective pesticide or rubbing alcohol on the plant in regular intervals until the pest disappears. Re-introduce the cactus to other plants only after ensuring complete and permanent removal of the pest.

So, these are some of the solutions to help you nurture your light green cactus back to its original color.

Leave a Comment