En EspaŅol

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
    
 
See a list of all Smarty Plants questions
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
Need help with plant identification, visit the plant identification page.
 
rate this answer
Not Yet Rated

Friday - October 28, 2005

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

QUESTION:

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?

ANSWER:

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

Ants and garden plants for Austin
November 03, 2012 - I am needy of companion plants that compliment and work well with the Lantana, Mexican Heather , and in the new beds that I am preparing where I was thinking in part to have passion flower (though is ...
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

Care of non-native dracaena potted plant
February 04, 2008 - Last summer I was given a corn plant that stands about 6ft tall. About 2 weeks ago it began to flower. Over time I've had maybe 3 or 4 of these plants and never had any of them bloomed. Is this no...
view the full question and answer

Late blooming Esperanza in St. Augustine FL
April 21, 2011 - I bought an Esperanza at a plant expo- I was told it was a Florida native Allamanda. It took me two years to figure out what I had. Mine grows 8 ft. tall and is huge! But it doesn't bloom until alm...
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

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center