As it turns out, there are several different reasons that a Christmas cactus could get yellow leaves. Let’s take a look at some of the causes and what can be done to fix the issue.
Too Much Sun
Even though this is a tropical plant, it will not tend to do well in direct sunlight. Full sun is appropriate during the spring and summer months, but when it becomes fall, the sunlight that the plant gets should be more indirect.
Giving the plant too much light will typically cause the leaves to look faded, but all you have to do is move the plant to an area where it is getting less light. In fact, during the blooming period, it should have about 12 hours of darkness a day.
Too Much Water
When you give a Christmas cactus too much water, the roots can become too moist and get root rot. This is a plant that does not need to be watered unless the top two inches of the soil is dry. In addition, during the dormant stage, the amount of water that you give the plant should be decreased.
Make sure that the pot that you use is well-draining so that it does not keep the water trapped at the roots. If your plant already has root rot, then you can remove it from the roots. If the plant is too damaged, it may not be able to be saved.
Root rot will look brown or black on the roots, and it may even have a musty odor that can be overpowering. Any area that is affected should be trimmed with a sterile knife that has been soaked in a combination of bleach and water.
Not Enough Nutrients
This is a plant that needs a lot of magnesium during the growing season, so you need to give it the nutrients that it needs, not just any fertilizer. Typically, the leaves of this plant will turn yellow if it is not receiving the nutrients that it needs. To make sure that the plant gets enough magnesium, you can mix a teaspoon of Epsom salt with a gallon of water to give to the plant once a month during the spring and summer. This mixture should not be given to the plant at the same time as you provide it with fertilizer. For more tips on feeding your Christmas Cactus, see this article I wrote here.
The Pot is too Small
When a pot that the Christmas cactus is planted in becomes too small, the roots become entangled so that they cannot drain as well. The plant will do fine is a somewhat crowded space, but when it becomes overcrowded, it will not receive the nutrients that it needs to grow, which is why the leaves turn yellow. This is a plant that will not need to be repotted more than once every two to three years. After the plant is repotted, do not give it fertilizer for about a month.
For more information on how to grow and care for your Christmas Cactus, see this tip guide here.
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