Red poinsettias are the traditional Christmas flower in the United States and throughout much of the world.White, pink and marbled colored plants are also available although not as popular as the red varieties. Beginning early October the plant must receive 14 consecutive hours of uninterrupted darkness each night but it must also receive bright light during the day. Poinsettias bloom naturally by Christmas if exposed to the normal period of darkness and daylight after October 1, provided the dark period is not interrupted by turning on the room lights at night. An artificial light source is often required to supplement low fall and winter sunlight.Usually by Thanksgiving, the dark treatment is no longer necessary. The key ingredient to producing a quality plant is good light during the day, and 14 hours of total darkness during bud set.
