En Español

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

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

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

Alternatives for non-native, invasive Dianthus spp.
July 02, 2006 - We're landscaping our 1963 ranch house in Austin, and we're trying to balance low water and wildscape concerns. Being just across the street from Shoal Creek means we're staying away from anything ...
view the full question and answer

White powder on non-native houseplants from Fort Davis TX
February 11, 2011 - I have a white powder on my houseplants that I can't figure out what it is or what to do about it? (Dracaena & Corn plants) Could be a fungus can you help? (can send a photo if you will tell me how t...
view the full question and answer

Non-native zoysia and bermuda grasses in Austin
July 11, 2013 - We have Bermuda grass in the front and Zoysia in the back yards. The back grass is fine but the front yard Bermuda isn't. We have watered once each week during the spring and during the past 3 weeks...
view the full question and answer

Replacements for non-native purple fountain grass in Austin
September 26, 2009 - Hi-- Just found out that the purple fountain grass I bought (fortunately on sale) is a) not native and b)not perennial. Dang it! If I can find the pots I'm taking it back. I have a part-shade wel...
view the full question and answer

Identity of mystery plant in non-native commercial forage mix
December 17, 2013 - Dear Smart One, I use a commercially prepared, fortified, chopped forage based on a mix of orchard and Timothy grasses. The bags are shipped in from out of State. However, I have been finding short s...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP | STAFF
© 2016 Lady Bird Johnson Wildflower Center