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
7 ratings

Sunday - May 11, 2008

From: Plano, TX
Region: Southwest
Topic: Trees
Title: Mountain laurel with new leaves or new seed pods
Answered by: Nan Hampton

QUESTION:

Each spring, my Texas Mountain Laurel seems to put new leaves only on selected branches (actually trunks), and put on seed pods on other trunks. It seems to be mutually exclusive: trunks with new seed pods get no new leaves, and visa versa. Is that normal? The tree in question is about 5-6 years old and seems healthy otherwise.

ANSWER:

You are very observant! Producing flowers and fruits (seed pods) and producing new leaves are both very energy-costly activities, so Sophora secundiflora (Texas mountain-laurel) does one or the other on a particular branch, but not both. The tip of each branch, the terminal bud, holds the primary growth areas of the plant, the apical meristems. The growth will be new leaves unless the cells of the apical meristem get a signal to form flowers instead. The signals for flowering include the maturity of the plant, the photoperiod, and temperature. Various plant hormones are involved, also—for instance, auxin for plant growth (as well as other plant activities) and florigen for flowering.

Some trees either add new leaves exclusively on all branches or bloom exclusively on all branches, but yours is not abnormal with some branches having new leaves and others bearing flowers and fruit. After I read your question, I did a survey of the mountain laurels in my neighborhood and elsewhere around Austin and saw many with new leaves on some branches and fruits on different branches of the same tree like your tree, as well as some with only seed pods on all branches or only new growth on all branches.


Sophora secundiflora

Sophora secundiflora

Sophora secundiflora

Sophora secundiflora

 

 



 

 

 

More Trees Questions

Damage to native elm in Texas
August 20, 2008 - We had a major landscape renovation done over the winter. One of the trees, an elm about 10 yrs old, remained in the bed although plants around it were removed. The tree has suddenly started turning...
view the full question and answer

Trees suited for rocky, caliche soil of Central Texas
September 20, 2011 - I need to replace aging ashes. I have planted 2 Monterey oaks, but I would like to know what else I could plant whose roots will grow well in NW Austin caliche, rocky soil? Thank you.
view the full question and answer

Native drought resistant evergreen plants for privacy hedgein clay soil in Texas
March 08, 2006 - My family would like to create privacy around our 4 acres of fence line. What native evergreen or fast growing bushes would work? We have terrible clay soil and need drought resistant plants.
view the full question and answer

Transplanting yaupon (Ilex vomitoria) trees, concern about cultivars
February 06, 2008 - I would like to place some yaupon in the perimeter areas of my yard. I own other rural property that has an abundance of yaupon and was considering trying to transplant some small bushes. Is yaupon ...
view the full question and answer

What are the native fruit-bearing plants in North America?
February 16, 2010 - What are the native fruit-bearing plants in North America?
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 | JOBS | SITEMAP | STAFF INTRANET
© 2016 Lady Bird Johnson Wildflower Center