A Christmas cactus is a beautiful plant and even more gorgeous when it blooms. Caring for a Christmas cactus is relatively easy because the plant does not require much attention. You only need to water the plant once a week and provide bright indirect sunlight.
Leaves falling off a Christmas cactus plant signifies a problem. Possible causes include overwatering, underwatering, low humidity, overexposure to direct sunlight and extreme temperature changes.
Why is My Christmas Cactus Dropping Leaves?
A healthy Christmas cactus will have beautiful green leaves. So when you see the leaves dropping, one of the following could be the reason.
Christmas cacti are natives of tropical forests and usually grow on other tree branches. They mostly get moisture from the air and therefore do not require much watering. While most plants prefer moist soil, the Christmas cactus does not.
Too much watering is dangerous because it can cause root rot. Additionally, the overwatered plant cannot absorb nutrients and water as required. You’ll see the plant dropping leaves, turning yellow, and eventually dying.
Although putting too much water is the main cause of overwatering, there are other causes, such as poor draining soil, planting the Christmas cactus in a large pot, and lack of drainage holes in the pot.
When you plant your Christmas cactus in a very large pot, you will have to put in more water which might be a little more than the plant needs. A pot with insufficient drainage holes will hold water for a long, making soil soggy and causing root rot.
Cacti are usually desert plants known to go for longer periods without water because their leaves can store lots of water. However, the Christmas cactus originates from the tropical forests of Brazil, where it is adapted to heavy rains and high humidity levels.
The cactus thus prefers moist soil (not wet) and a humid environment. Watering is essential for photosynthesis and the general growth of the plant. Lack of water will make the plant enter drought mode and shed leaves to survive.
When watering a Christmas cactus with very dry soil, you should poke some holes into the soil to enable the water to reach the bottom of the pot. Keeping the Christmas cactus in a humid room will help minimize the watering schedule.
You should water the plant more during summer and less during winter. Also, if you want the Christmas cactus to bloom, you should reduce watering to allow the plant to enter dormancy, which is critical for blooming. Increase the watering schedule a little bit more during flowering.
3. Too much Fertilizer
Fertilizing a Christmas cactus is crucial because it gives the plant essential nutrients. However, if you put too much fertilizer, you will cause toxicity in the roots. The roots will not function properly, and they will not be able to absorb water and nutrients.
The plant will dehydrate, causing the leaves to drop. If not resolved immediately, the plant will eventually die.
4. Too much sunlight
Christmas cactus does not like direct sunlight because the sun will scorch their leaves. Overexposing the plant to sunlight during summer will make it drop its leaves. Keeping the Christmas cactus near a window that receives direct sunlight will also cause the leaves to fall or turn red.
Exposing the Christmas cactus to too much heat or cold will cause the leaves to drop. Extreme temperature changes during summer or winter aren’t healthy for the plant.
Also, keeping the plant near a heat source or cold draft, such as an air conditioner vent, will cause the plant to drop leaves.
How to fix the leaves dropping problem
If your Christmas cactus experience the problems mentioned above, here is what to do to keep your holiday cactus healthy and happy.
Too much or too little water will harm your Christmas cactus, causing it to drop leaves. So you should make sure to put in sufficient water. Typically, a Christmas cactus should be watered once a week, preferably when the top inch of the soil is completely dry.
However, the weather and temperature will determine the amount of water needed. The plant will require slightly more water during summer because it will dry up quickly but requires less water during winter.
Also, in a humid environment, the Christmas cactus will need less water as it will draw moisture from the air.
Before adding more water, use your finger or a stick to check the moisture content in the soil. You should only water if ⅓ of the soil (topsoil) is dry. When planting a Christmas cactus, use well-draining soil and a pot with proper drainage.
The pot should not be very big, so it does not hold more water than the plant requires. Using a mixture of potting soil and river sand is very good. But you should use potting mix formulated for cactuses or succulents.
Detox the plant
If you suspect the leaf dropping is caused by too much fertilizer, it is essential to detox the plant. Over-fertilized soil will have white crusts on top, which are nutrient build-up.
Below are two methods you can use to fix the problem.
- Remove the Christmas cactus from the pot and check for damaged roots. Trim and wash the damaged parts gently to remove the excess salt build-up. Then repot the plant in a fresh soil mix.
- Flush the soil with water for 5 minutes to dissolve and wash the excess salts. You should wait for at least six months before fertilizing the plant again.
Keep the plant in the recommended temperature range
A Christmas cactus will thrive well in temperatures between 15 – 29 degrees C. When the temperature gets below 10 degrees C, the Christmas cactus will start to drop its leaves. To resolve the problem, adjust the temperature as required.
Furthermore, do not keep a Christmas cactus near a heat source or cold drafts.
Move the Christmas cactus away from direct sunlight
Put your Christmas cactus in a bright room with indirect sunlight. If you love keeping the plant outside during summer, ensure it’s under a shade, but you should bring it indoors during cold winters.
A Christmas cactus will drop its leaves for various reasons, such as overwatering, underwatering, very cold or hot temperatures, exposure to direct sunlight, and too much fertilizer. To help the plant, you need to identify and fix the leaf drop’s cause.
“Holiday Cactus FAQs,” PURDUE University
“How often should I water a Christmas cactus?” University of New Hampshire
“Care of Christmas Cactus Important After Holidays,” the University of Arkansas Extension
My name is Diane M Lewik, and I am the founder of this website. I am a degree holder in plant biology from the University of California – Berkeley. Over years, I have cultivated a vast collection of succulents and I have learned a great deal about how to grow and care for these unique plants.