Missing its bloom trigger

What's happening

Christmas cactus is a short-day, cool-temperature bloomer. It only forms buds when it gets long uninterrupted nights — roughly 12–14 hours of darkness — together with cool temperatures around 50–60°F for several weeks in fall. Warm rooms and evening lamplight near the plant interrupt that signal, so it grows happily but never triggers flowering.

How to fix it

Starting about six to eight weeks before you want blooms, give it long, truly dark nights: tuck it in a spare room or closet, or cover it, for 12–14 hours of uninterrupted darkness each night, and keep it on the cool side (50–60°F at night). During the day, return it to bright indirect light. Keep watering light and stop feeding during this period. Once buds form, move it back to its normal cool, bright spot and resume even watering — and don't shuffle it around once buds appear.

This is general guidance based on common symptoms; individual plants vary.