Why is my cereus cactus turning yellow?

Answered by Robert Flynn

Cereus cacti are generally low-maintenance plants, but they can still face issues that cause their leaves to turn yellow. One common reason for this is overwatering, which leads to root rot. When the roots are constantly saturated, they cannot receive the oxygen they need and begin to decay. As a result, the plant’s overall health deteriorates and its leaves may turn yellow.

To prevent overwatering, it is important to understand the watering needs of your cereus cactus. These plants prefer well-draining soil and should be watered only when the top inch of soil feels dry. It is crucial to allow the soil to dry out between waterings to prevent waterlogged conditions. Additionally, ensure that the pot has adequate drainage holes to allow excess water to escape.

If you suspect root rot in your cereus cactus, gently remove the plant from its pot and examine the roots. Healthy roots should be firm and white, while rotting roots will appear brown, mushy, and may emit a foul odor. If root rot is present, it is essential to take immediate action.

To address root rot, you will need to remove any affected roots using a clean, sharp pair of scissors or pruning shears. Make clean cuts slightly above the rotted area, ensuring that you remove all the decayed parts. It is crucial to sterilize your cutting tool with rubbing alcohol or a bleach solution before and after use to prevent the spread of disease.

After removing the damaged roots, allow the plant to dry out for a few days. During this time, refrain from watering the cactus to give the remaining roots a chance to recover. Once the plant has had time to dry, you can repot it in fresh, well-draining soil. It is advisable to use a pot slightly larger than the previous one to allow for root growth.

After repotting, gradually reintroduce watering, ensuring that you do not overdo it. Stick to a watering schedule that allows the soil to dry out between waterings, and always check the moisture level before adding more water. Over time, with proper care and attention, your cereus cactus should recover and its yellowing leaves should gradually regain their healthy green color.

Yellowing of cereus cactus leaves is often a result of overwatering and root rot. It is crucial to adjust the watering frequency, provide well-draining soil, and maintain proper drainage to prevent these issues. If root rot does occur, prompt action is necessary to remove affected roots and allow the plant to recover. By addressing these concerns and providing appropriate care, you can help your cereus cactus thrive and maintain its vibrant appearance.