The Christmas cactus is a stunning houseplant that blooms in the dead of winter producing colorful flowers. Christmas cactus leaves turning purple is commonly a sign of distress from an issue that’s affecting its health and growth.
Reasons for Christmas cactus discoloration may include overwatering, too much direct sunlight, nutrient deficiency, and extreme temperature.
Generally, Christmas cacti prefer bright indirect sunlight, well-draining soil, warm temperatures between 60-70°F (15-21°C), and humid environments. Fertilizing it during the growing season (spring and summer) helps promote growth.
Why is my Christmas Cactus Turning Purple?
A slight purplish tinge on the leaves of a Christmas cactus is usually not an issue as long as you are taking good care of the plant. You should be concerned if your cactus leaves visibly turns purple from their usual green color.
Possible reasons for this problem include the following:
1. Lack of nutrients
Christmas cactus leaves turning purple is a common sign that your plant is lacking important nutrients. Like other plants, cacti need nutrients for growth and blooming. In their natural habitat, these plants enjoy a constant supply of nutrients from decomposing tree leaves and bark.
If you haven’t met your Christmas cactus fertilizer needs for a while then it’s a reason why it’s losing its lustrous green color. Over time potted plants use all the nutrients available in the provided soil and there is a need to keep replenishing.
What to do
Start feeding your Christmas cactus on a monthly basis during the growing season in spring and summer. Apply a recommended houseplant fertilizer like 10-10-10 plant food diluted with water to 50% strength or as directed on the product label.
Christmas cactus also needs more magnesium than any other houseplant. Fertilize monthly with magnesium sulfate solution (Epsom salt) diluted at a ratio of 1 teaspoon to 1 gallon of water, but not the same week you applied fertilizer.
Stop fertilization of the cactus during late summer for greater bud formation in the fall. This is also the best time to cut back on watering your Christmas cactus as you prepare to place the cactus in darkness to stimulate blooming.
2. Compacted roots
A Christmas cactus thrives in small quarters and it likes to be root-bound. However, in time the roots outgrow the small pot and become heavily compacted. When roots are crowded, it becomes difficult for them to take up and supply nutrients to the plant.
The obvious signs of this problem include stunted growth, leaves turning yellow or purple, and quick wilting. Before it comes to this point, you will notice that roots are popping through drainage holes at the bottom of the soil or above the soil.
What to do
If you identify this to be the problem, repot your Christmas cactus. Transfer the plant to a slightly larger container filled with a well-draining soil mix for succulents. Spring is the best time to repot a Christmas cactus when flowers have faded and the plant is entering into active growth season.
3. Too much sunlight
If you forget your Christmas cactus outdoors for too long during the summer months or placed it in a place that receives direct sunlight then it’s the reason your plant is turning purple. Christmas cactus loves bright light during fall and winter but direct sunlight will scorch and discolor the plant.
What to do
Move the Christmas cactus to a shaded place and ensure it’s getting bright indirect light henceforth. Indoors you may place it near the east-facing window or under a grow light.
Outdoors, place it under the shade of other plants, or hang it on your porch to prevent sunburn. You should also keep your cactus out of the sun during midday hours when the sun is at its hottest.
4. Water issues
Watering a Christmas cactus is typically a delicate balance. Too much or inadequate watering isn’t healthy. Christmas cactus doesn’t like waterlogged soil. Christmas cactus leaves turning red or purple is majorly a sign of overwatering.
Excess moisture in the soil stops oxygen from reaching the roots and this makes them suffocate and die. As a result, the uptake and supply of nutrients and water stop.
Less watering on the other hand can also damage the foliage of a Christmas cactus. Although not directly linked to leaves turning purple, it can cause dehydration – characterized by leaves falling off, wilting, and even death of a plant.
What to do
Water your cactus regularly but only when the top inch of the soil feels dry to the touch. Insert your finger in the soil to test for moisture. Water thoroughly and let the excess water drain out.
Do not let the cactus sit in any standing water and make sure the soil mix is draining well and the drainage hole at the bottom of the pot is working.
The overwatered Christmas cactus can be saved by removing the damaged roots and repotting the plant in a fresh soil mix. Remember to thoroughly clean and sterilize the pot before reusing it.
5. High temperatures
Fluctuations in temperature can harm Christmas cacti. These plants prefer daytime temperatures of 70-80°F (21-26°C) and an evening temperature of 60-65°F (15-18°C) respectively.
An increase in temperature above 80°F can cause the leaves of a Christmas cactus to turn purple, wilt, or get wrinkled. On the other hand, extremely low temperatures below 50°F can harm or kill the plant as well.
What to do
Keep your Christmas cactus in the recommended temperature range. Move the plant away from heating vents, fireplaces, and cold drafts. However, cool temperatures around 50-55°F are essential for blooming.
It’s quite common for the leaves of the Christmas cactus to turn purple when the plant is in distress. To address the issue, be sure to maintain the optimal growing conditions of the plant, such as proper temperature, watering, light, and nutrient levels.
- University of New Hampshire: How often should I water a Christmas cactus?
- North Carolina University Extension: Christmas Cactus Care
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.