Although many times poinsettias are treated as disposable holiday decor, there’s no reason to throw out your poinsettias after the holiday season has ended. With the proper care, you can keep your poinsettias so they’ll bloom again the next year. The plant needs to receive a certain amount of light in order to bloom again.
Indoors, keep your poinsettia in a window that faces south or west so it will get enough sunlight. Provide the plant with water whenever the top inch of its soil has dried out. Once the temperature in your region is safely past the 45-degree-Fahrenheit mark, you can move your poinsettia outdoors for the summer. Be sure that cold weather isn’t forecasted to return, as temperatures of 45 degrees Fahrenheit or below will harm your plant.
Choose a spot for your poinsettia outdoors where it will get bright sunshine in the mornings. At this time, also cut the plant back to about six inches above the ground, making sure to leave about a third of the foliage on the plant. Once new leaves begin to emerge, you can pinch off the new shoots at their tips to encourage bushier growth. Keep the poinsettia watered, and fertilize it to encourage healthy growth while it is outdoors.
In the fall, you will need to dig up your poinsettia and put it back into a pot so it can be moved indoors. Make sure to get the poinsettia out of the garden before the temperature falls to 45 degrees Fahrenheit, as that is the temperature at which the poinsettia begins to sustain cold damage. You will probably need a larger container for your poinsettia after it has spent the summer in the garden outdoors.
Move your poinsettia to a spot inside where it will get 14 consecutive hours of uninterrupted darkness and 10 hours of bright light each day. You can place a cardboard box over the plant to keep it in the dark if you do not have a room that will stay dark for 14 hours a day. After two months of this schedule, your poinsettia plant should begin to produce colored bracts again.