Your poinsettia should be moved outdoors during summer, so it is important to keep it in good condition now. Often, blooms will last for months after January. The first important part is to remove the colored foil covering the outside of the pot. It traps water if it has no holes and plants can be marinating in several inches of water, rotting the roots. Poinsettias need to be close to a west or south window and receive some sun during the day. Michigan State University Extension suggests watering it when the top inch of soil is dry.