Poinsettia – Forcing
Q: I have three poinsettia plants which I’ve kept for four years. Last year, they changed color in the summer. How can I get them to change color at Christmas?
A: Your poinsettias were only doing what comes naturally when the bracts changed color in the summer.
The fact of the matter is that the bracts around a poinsettia bloom will change color 10 – 14 weeks after the bloom has appeared.
You grew your poinsettia in conditions that made the plants produce blooms in March. Twelve weeks later and you had Christmas in June!
In their native Mexico, poinsettias bloom in early January.
Greenhouse growers manipulate the temperature and light around their plants to make them turn color just before Christmas.
You can make your plants initiate blooms by covering them each day with a cardboard box for fourteen hours beginning in late September. Water them normally and leave them outdoors until cool weather arrives.
Move them indoors then but keep up the fourteen hours of daily darkness until early November. You should see buds appear at the end of each branch. If the plant is kept in a cool, bright window you’ll have colorful bracts just in time for the holidays!