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 - September 03, 2010

From: Austin, TX
Region: Southwest
Topic: Trees
Title: Pecan Trees in Austin, TX prematurely losing their leaves.
Answered by: Marilyn Kircus

QUESTION:

Why are the leaves on the pecan trees falling so early this year.

ANSWER:

I suspect that you are seeing cultivars of pecans which may be much less resistant to stress and diseases, although “native” trees are possibly also being stressed to the point of losing their leaves.  “Native” pecans are recommended for yard trees because of their greater natural resistance to stress and disease and because they don’t kill themselves by producing more nuts than they can actually support.  “Native” in this context refers to trees that occur naturally and are not cultivated varieties. 

Second, I’ve seen lots of pecan trees that lose leaves and also limbs when they don’t get enough water. The leaf fall is most likely a result of the current drought following on the heels of ample spring rains.  I’m seeing lots of area trees shedding leaves as the drought goes on here.  The excellent winter and spring rains we had encouraged lots of lush foliage on our trees.  As a natural defense in the face of diminishing water availability, local trees are doing what plants do in this situation, they’re defoliating to reduce transpiration and protect the organism. 

Third, through researching the problem of early leaf abscission – what you’ll find in scientific writings describing leaf drop – there are several other possible causes:

  1. Nitrogen deficiency causes leaves to yellow and in serious cases to fall off. 
  2. Downy spot can cause early leaf loss in susceptible cultivar like 'Stuart', 'Pawnee' and 'Moneymaker'.  It’s possible our wet spring gave this fungus a foothold.  
  3. The Twig Girdler insect can cause small twigs to drop in late summer. Check to see if  the leaves are attached to a small portion of the twig. There will be a perfect circle cut in the bark if this is the culprit.  

This question falls under the bailiwick of State Agriculture Extension Services and I found several useful  on-line publications.  Check out the following links: 

  1. From Texas A & M – Evaluating Pecan Problems2. 
  2. From the University of Florida - The Pecan Tree  
  3.  From the Dirt Doctor  who researches organic growing methods here in Texas – Pecan Tree

So, although I can’t give you a definitive answer, hopefully this information will assist you in determining why pecan trees in Austin are shedding their leaves prematurely.

 

 

More Trees Questions

Need suggestions for planting trees in poor soils in Austin, TX
February 27, 2015 - Due to the clay soils and poor drainage in East Austin, what ornamental trees do you normally suggest?
view the full question and answer

Mexican Sycamore trees grown from seed
November 15, 2011 - If someone is selling an alleged Mexican Sycamore grown from a seed harvested from a mature tree growing in Austin, is it likely to be a TRUE Mexican Sycamore -- or has it most likely been pollinated ...
view the full question and answer

Non-native, invasive mimosa trees in Vincennes IN
April 29, 2014 - I have 3 Mimosa trees here in Vincennes, Indiana and so far none of them are leafing out this spring (4-28-14) Do you think that this past winter could have killed then?
view the full question and answer

Problems with fruit of Mexican Plum from McKinney TX
May 19, 2013 - MY Mexican plum tree (about 5 years old) has small fruit on it. Some of them are severely deformed, and look rotten almost. They are bumpy and ragged looking. Or they are pasty white,rotten and dried ...
view the full question and answer

Source for dwarf red mulberry from Spring Hill TN
December 08, 2012 - Hello: Where can I buy a dwarf red mulberry tree in the USA? Thanks
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