Unlike other varieties of flowering cactus, the Christmas cactus has flat leaves with scalloped edges and is designed to bloom in the deep of winter (other varieties have spiky or furred edges and bloom at different times of year). You can help ensure your Christmas cactus will be ready for the season by taking a few preventive steps in the fall.
Beginning in late October, place your Christmas cactus in a dark, deep closet for 12 hours per night. In the morning, place your cactus back in its typical area. After 6 to 8 weeks of these sessions, buds will begin to form. Stop moving your plant in any way after the buds form. These are fragile blossoms that can easily drop off during movement, depriving you of the blossoms you've worked so hard for.
If you'd prefer to keep your cactus in one place, ensure that the room is quite cool. Beginning in November, keep your Christmas cactus in a location that is 55 to 60 degrees Farenheit at all times. The cool air will encourage your plant to set blooms. Once blooms appear, you can carefully transport your plant to its traditional sunny location.
To ensure that the blossoms stay on your plant, and that your plant is encouraged to allow those blossoms to bloom, provide a flowering plant fertilizer during the month that your cactus is in bloom. Each week, feel the soil around your plant and provide more water when the soil feels dry. Your plant may require more water as it blooms, so check it often. Remove any spent blossoms to encourage your plant to produce more flowers. If your flowers seem to bleach out, the plant may be exposed to too much sunlight. Carefully move it to a more shaded location.