How do I care for my poinsettia?
The key points in caring for your poinsetta (Euphorbia pulcherrima) are adequate light, care in watering and stable temepratures both day and night. For best results, maintain 65°-70°F during the day; 55°-60°F at night. Your plants should get 4 hours of direct sunlight daily and be watered only after the top of the soil has dried out. Environmental humidity above 50% is desirable.
Courtesy of NYBG Plant Information