Move the poinsettia inside to a bright sunny area, by the end of September to early October. Fertilize it monthly, and make sure it has ample water. Starting the first of October, and continuing through November, it needs total darkness from early evening until morning, and bright light all day. Remember, the light cycle is just as important as the dark cycle. During the dark cycle, it can t have any light at all.
Many people find it easier to cover the plants for the dark cycle to prevent any light getting in.
Then take the covering off in the morning. The Arkansas Cooperative Extension Service offers its programs to all eligible persons regardless of race, color, national origin, religion, gender, age, disability, marital or veteran status, or any other legally protected status, and is an Equal Opportunity Employer. The mention of any commercial product in this web site does not imply its endorsement by the University of Arkansas Cooperative Extension Service over other products not named, nor does the omission imply that they are not satisfactory.