The key points in caring for your poinsettia houseplant (Euphorbia pulcherrima) are adequate light, care in watering and stable temperatures, both day and night.  For best results, maintain 65°-70°F during the day; 55°-60°F at night. Your plants should get indirect sunlight daily and be watered only after the top of the soil has dried out. Environmental humidity above 50% is desirable.

Inducing the plant to re-flower in subsequent years requires a strict seasonal regimen that can be difficult to adhere to in a home. You can find a list of steps to follow in our Guide to Poinsettia, as well as complete instructions for the plant's care.

Courtesy of NYBG Plant Information