If given good care in the home, a poinsettia should remain attractive for two to three months. Toss the poinsettia when you grow tired of it or it becomes unattractive.
For those home gardeners who enjoy a challenge, it is possible to get the poinsettia to bloom again next season. Cut the stems back to within 4 to 6 inches of the soil in March. The poinsettia also may be repotted at this time. When new growth appears, place the poinsettia in a sunny window. Continue to water the plant when the soil surface becomes dry to the touch. Fertilize every two weeks with a dilute fertilizer solution.
In late May, move the poinsettia outdoors. Harden or acclimate the plant to the outdoors by placing it in a shady, protected area for two or three days, then gradually expose it to longer periods of direct sun. The poinsettia should be properly hardened in seven to ten days. Once hardened, dig a hole in an area that receives six to eight hours of sunlight and set the pot into the ground. To obtain a compact, bushy plant, pinch or cut off the shoot tips once or twice from late June to mid-August. Continue to water and fertilize the plant outdoors.
The poinsettia should be brought indoors in mid-September. Place the plant in a bright, sunny window. The poinsettia is a short-day plant. Short-day plants grow vegetatively during the long days of summer and produce flowers when days become shorter in fall. To get the poinsettia to flower for Christmas, the plant must receive complete darkness from 5 p.m. to 8 a.m. daily from early October until the bracts develop good color, usually early December. Protect the plant from light by placing it in a closet or by covering with a box. During the remainder of the day, the poinsettia should be in a sunny window.