Poinsettias are phototrophic, and just like all plants they get their energy from the sun. The only difference is that this weird little plant takes the need for proper light to a different level. Poinsettias bloom based on the length of day. When the day length is correct the plant will bloom and the bracts (the red part) will begin to color. North Carolina is not the native range for the poinsettia of course so we have to take a little extra step to help it to reach this blooming stage. In order to force our plants to bloom, we need to make sure that the plant has a steady 14 hours of darkness and 6-10 hours of bright sunlight. The darkness is imperative to get your plants to re-bloom. Even a slight interruption in the darkness can cause the plants to not bloom. The best way to make sure they are getting enough darkness is to place the plant in a closet and set a timer for 14 hours each day. In this process do not open the door to that closet at all. If this is done correctly your poinsettia should begin to color up in about 6-8 weeks and be in full bloom in 12 weeks. If we count backwards that means we must begin our darkness process or what is technically known as a photoperiodic treatment around October 1 for the plants to be showing their full glory by Christmas.
After the Christmas season reduce watering of your plant but do not let the stems shrivel. This will allow the plant to enter a dormant state so you can store it for the winter. In the spring after all frost danger has passed cut the poinsettia back to 6-8 inches in height and repot the plant into a bigger pot. Place it outside in a partly sunny location that is protected from the wind. As the plant grows, pinch the new growth to keep the plant compact and bushy. As we reach the fall you can begin your photoperiodic treatment for yet another year of great color from your favorite poinsettia.