8 Common Mistakes That Keep Your Christmas Cactus from Blooming During the Holidays

Christmas cactus plants bloom when the days grow short in winter, producing big, tropical-looking flowers just in time for the holidays. However, if these succulents don’t receive the right care, they may not flower at all, or their buds may fall off before they open and leave you with a bloomless plant.

Here’s a look at some of the most common issues that keep Christmas cacti from flowering, and ways to ensure your plants bloom bright this holiday season.

1. Too Much Light

Unlike most plants that flower during the longer days of spring and summer, Christmas cactuses are short-day plants that form buds and flower only when the days get short in winter. Unfortunately, that means that if you keep your plants in a brightly lit room leading up the holidays, they may get too much sun and not flower at Christmas.

For peak flowering, Christmas cactuses should be kept in a spot that stays dark for about 12 to 14 hours a day for 8 weeks, beginning in mid-October. You can accomplish this by placing your plants in a room you don’t use in the evening and keeping the lights off until morning. An alternative is to cover your plants with an old blanket or box at night to block out the light and remove the covering in the morning.

2. Not Enough Light

Although Christmas cactuses require long, dark nights to form flower buds, they still need plenty of light during the day to have enough energy to bloom. To achieve this, position your plants in a location that receives at least 4 to 6 hours of bright, indirect light per day. If you moved your plants into a dark room or under a box for the evening, remember to remove those coverings in the morning!

3. Warm Temperatures

Monitoring light levels is the number one way to increase flowering in Christmas cactuses, but these plants also bloom better in cooler temperatures. Ideally, daytime temperatures should be around 65 to 70°F, and nighttime temperatures should be between 55 and 65°F throughout fall. Some people turn the thermostat down a few degrees, while others may choose to move their plants into a garage or potting shed that’s a little cooler than indoors. Make sure these tropical plants are never exposed to freezing temperatures!

4. Fertilizing at the Wrong Time

To flower, Christmas cactuses require a fair amount of nutrients. They should be ' with a liquid organic houseplant fertilizer diluted to half strength with water. However, these plants should only be fertilized from the moment new growth starts in spring to roughly the end of August. If you continue to fertilize Christmas cacti through fall and into winter, they produce more new leaves instead of blooms. 

5. Improper Watering

Watering stress is also a reason why Christmas cactuses flower less, so it’s important to stick to a regular watering schedule. Throughout the year, water these plants when the top 1 inch of soil feels dry and make sure they continue to receive regular deep waterings in autumn.

Christmas cacti often need more water when their flower buds are forming, though overwatering them may lead to root rot and other issues.

6. Moving Budding Plants

If you move Christmas cactuses into another room to reduce light levels in autumn, wait until the flower buds start to open before returning your plants to a spot where you can enjoy them. An earlier change in location may cause stress and potentially make the cactus drop flower buds before they open.

7. Low Humidity Levels

Christmas cacti need more humidity than standard desert cactuses. If they get too dry, they may drop their flower buds or not flower at all. These plants thrive in humidity levels are between 50 to 70% year-round, and they may need a humidifier or pebble tray if the air in your home is on the dry side.

Placing these plants in a humid and well-lit bathroom or kitchen also increases humidity levels and keep Christmas cacti from drying out.

8. Not Repotting

Over time, potting soil becomes depleted in nutrients or gets too dense to drain properly, leading to poor or no flowering in Christmas cacti. That's why it is important to repot your Christmas cactus with fresh potting soil in spring when your plant starts to produce new growth. Repotting every year or two maintains the quality and freshness of the soil. However, if you did not repot your plant in spring, repotting Christmas cacti just before the holidays is not recommended because the transplant shock may cause your plants to lose flower buds.