From:TULSA, OK Region: Southwest Topic: Non-Natives Title: Hours of darkness for non-native poinsettia to bloom Answered by: Joe Marcus and Nan Hampton
I have a poinsettia from last Christmas still alive. I was told to get it so many hours of darkness. Do you know how many hours? When would be the best time to start displaying the plant again?
The poinsettia (Euphorbia pulcherrima) is native to southern Mexico. They are "short-day" plants which means that flowering is in response to long nights. It varies among cultivars, but 16 hours of uninterrupted darkness per night for several weeks is sufficient to induce the flowering response in any poinsettia. Any light at all will delay or stop the flowering response. There are classic stories about automobile lights from nearby highways and even flashlights from night watchmen delaying flowering on greenhouse grown poinsettias. People commonly put their plants in a dark closet each night for a few weeks in the fall to induce flowering and the red bract development (they bring them out each day). It is a little late to get your plant to flower by Christmas, but you can still get it to turn red just the same. If you start now, it may be red in time for St. Valentines Day! You can read more about the care of poinsettias.
More Non-Natives Questions
Care for 'Winchester' honeysuckle? June 05, 2009 - I have a Winchester honeysuckle that is now in full bloom. Do I "deadhead" the blooms after they die off? view the full question and answer
Leaves shriveling on non-native Japanese maple in Redmond WA July 18, 2009 - My husband and I bought a Japanese Maple 3 years ago which we planted in an old wine barrel for our patio, along with some ivy and grass to keep the surface covered. Until recently, it has been doing ... view the full question and answer
Possibility of replacing Bermudagrass with native grasses and wildflowers November 24, 2008 - Are there any native grasses and wildflowers that can compete with bermuda grass to make a nativ-y wild area without removing the bermuda? view the full question and answer
Non-native arica palm October 21, 2008 - I have been watering an arica palm in my house in Va. Beach, VA. The leaves continue to get brown, dry up and die.
I'm not sure if it has a disease or something else.
Can you help? view the full question and answer
Care of non-native calla lilies July 15, 2005 - How should I protect my calla lilies during the winter? If it helps you any, I live in South Carolina. And also will too much water hurt them? We have had massive amounts of rain. view the full question and answer