Christmas cactus, also known as Schlumbergera bridgesii, is a popular holiday plant that is commonly used to decorate homes during the winter months. It is a succulent plant that is native to Brazil and is known for its ability to bloom during the winter holidays. When it comes to putting Christmas cactus in the dark, it is recommended to do so during the night hours. This will help the plant conserve energy and promote healthy growth. The plant should be kept in a dark place for around 12 hours each night.