Re-Coloring Poinsettia: Can’t handle tossing your holiday poinsettia this year? We’ve got the secret to getting your poinsettia to re-color, year after year. Re-establishing a solid green Poinsettia plant from last year back to its unique red color is no problem if you observe a couple of basic guidelines. Poinsettias (Euphorbia pulcherrima) require 14 hours of total darkness per day for eight weeks before they can be displayed. PBS-TV’s Loren Nancarrow shows you the secret to getting your poinsettia to…