Fairy castle cactus is a heat-loving plant that gradually stops growing and enters a dormant state during the winter. When the outdoor temperature drops below {Tolerable_growing_temperature_min}, it should be moved indoors for cultivation. Choose a location near a south-facing window to provide as much sunlight as possible. If there is insufficient natural light, supplemental lighting can be used. When the temperature falls below {Suitable_growth_temperature_min}, the plant's growth slows down, and watering should be reduced or stopped to prevent root rot. For Fairy castle cactus grown outdoors, watering should be completely halted during low temperatures. If feasible, you can set up a temporary greenhouse for insulation or use materials such as plastic film or fabric to wrap the plant during cold temperatures.