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

Replacing non-native invasives with native grasses and wildflowers from Round Rock TX
April 04, 2012 - I have a small piece of property (1.5 AC) East of Austin, Texas that get's overgrown with weedy vegetation (johnson grass, dandelion, and some tall yellow flowering plant that I see all over the medi...
view the full question and answer

Regulations for transporting plants to Texas from Florida
July 29, 2008 - We are relocating to TX from FL, I have a collection of potted palm trees and quite a few potted tropical plants (none are invasive)that I would like to bring with us, we will be traveling by car and ...
view the full question and answer

Plants for pots outdoors in winter in Virginia
October 02, 2008 - Hi Mr. Smarty Plants, I was wondering what plants would be best to grow outdoors, in pots, in Virginia, in the winter? This is a lot of restrictions but we just need 2-3 plants for our office pati...
view the full question and answer

Non-native Asclepias curassavica
March 09, 2005 - I have some plants given to me by a neighbor, here in Florida. She says they are called Butterfly Reel or by another name Asclepias Curassavica. I have been unable to locate any info. on this plant. ...
view the full question and answer

Red pods on Canna Lilies from Windsor VA
July 21, 2013 - What are the dark red pods on my canna lilies?
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