"But the major thing to remember is that poinsettias require long periods of darkness starting in October in order to achieve their bright displays during the holidays. That means about 15 hours a day, from 5 p.m. to 8 a.m., during which the plant is kept in a dark closet or under a cardboard box, with no light at all, to produce what is called a 'shorticulture day.'"
—George Bria, "A touch of history enhances poinsettias," The Associated Press, November 13, 2000