Christmas cactus can be difficult to get to bloom, but here are some tips that may help. First, make sure you provide the plant with bright but indirect sunlight, and keep the soil evenly moist but not soggy. Additionally, feed the plant a balanced fertilizer with high levels of phosphorus once a month during the growing season. Finally, the plant needs to be in a cool room at night for at least 14 hours to mimic the short days and cooler temperatures of winter.