When to Put a Christmas Cactus in the Dark

You can get a Christmas cactus to bloom by keeping it in the dark. A Christmas cactus is a short-day plant and must be kept in uninterrupted darkness for twelve to fourteen hours daily for six to eight weeks to produce flower buds.

Additionally, a temperature range of around 60-65°F (15-18°C) is needed for bud formation. Once the buds have formed, you can gradually increase the temperature to around 70-75°F (21-24°C) to help the flowers open fully.

The best time to put your Christmas cactus in the dark is mid-October to early November. This will allow you to enjoy beautiful flowers throughout the Christmas holiday. Under good care, the flowers can last three to six weeks.

You should discontinue putting the Christmas cactus in the dark as soon as the buds form. Instead, put it in a bright room with indirect sunlight. Avoid moving the plant further as it may result in flowers or buds falling off buds due to temperature fluctuations.

You can also get a Christmas cactus that’s already flowering on Amazon if you aren’t lucky to get yours to bloom.

Christmas cactus blooming requirements

To encourage the Christmas cactus to bloom, you must provide optimal temperature, humidity, water, light, and darkness conditions.

1. Light Requirements

Keep your Christmas cactus in a bright room with indirect sunlight during the day and total darkness at night. The Christmas cactus should be in darkness for about twelve to sixteen hours. Afterward, move it to a bright spot for the rest of the day.

When placed in the dark, ensure the darkness is not interrupted because even a little light will disrupt the process, and you will have to start all over again. The best places to keep your Christmas cactus in the dark include the following.

A Closet: Put your Christmas cactus in a closet that you will not use for 12 – 14 hours a day. Take whatever you need from the closet before placing it in your to avoid interruption in the formation of flower buds.

Garage: Most garages are dark and will be an ideal place for your Christmas cactus. Ensure to keep it in the darkest corner of the garage. If your garage has windows, you should cover them with a dark curtain to ensure light from outside does not shine inside the room.

Closed box: Suppose your house has too much light and lacks any dark place to keep the plant. Simply cover the Christmas cactus with a larger box. Ensure the box is not touching the plant.

2. Water requirements

Unlike most garden plants that require a generous amount of water to bloom, the Christmas cactus doesn’t. The plant will require little water since it will not encounter direct sunlight and will spend the most time in the dark.

Normal watering should resume as soon as the buds start opening. Additionally, mist the plant with water when the humidity level is low. Dry air and inadequate moisture in the soil may cause the flowers to wilt or drop.

Generally, before watering your Christmas cactus, poke a hole in the soil to check for moisture level. Only water when the top one inch of the soil is completely dry. Too much watering causes the cactus to rot and die.

3. Temperature requirement

The Christmas cactus requires very cool temperatures when kept in the dark. The temperatures should be between 60- 65 degrees Fahrenheit. Prolonged temperatures below 50 degrees Fahrenheit may harm or kill the plant.

Also, when kept at a temperature above 65 degrees Fahrenheit, the plant will not bloom.

4. Humidity Requirements

Christmas cactus native forests are humid, and the plant loves to draw moisture from the environment. Therefore, you should keep your house or the garden where you keep your Christmas cactus humid. You can also spray water on the plant leaves once or twice weekly.

Conclusion 

A Christmas cactus thrives better in bright, indirect light and can be kept in the house or the garden under shade. The plant can be kept in the dark to encourage blooming. It should be kept in absolute darkness for at least twelve hours and transferred to a place with indirect light for the rest of the day.

When in darkness, monitor the temperature and moisture conditions for optimum blooming.

References:

“Christmas cactus,” University of Florida Gardening Solutions

“Thanksgiving and Christmas cacti,” Clemson Cooperative Extension

“Holiday Cacti Care,” Pennstate Extension