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?


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
3 ratings

Thursday - January 26, 2012

From: Denton, TX
Region: Southwest
Topic: Diseases and Disorders, Trees
Title: Live oak leaves yellowing from Denton TX
Answered by: Barbara Medford


In autumn of 2010 I planted 10 live oaks about 6 to 7 ft. tall. I have see that during the month of Dec. 2011 to Jan. 2012 they are showing some yellow leaves. What can I do to help them?


There are a number of possible causes for yellow leaves. Aside from the fact that this has been a very hard year for heat and drought, there are several other things that can cause yellowing. If you just recently planted the oak, it could be suffering from transplant shock,

Yellowish leaves could indicate chlorosis, or lack of iron being taken up by the tree from the soil. This is often caused  by poor drainage and/or dense clay soil, which causes water to stand on the roots. Again, this could  be a problem caused by planting, perhaps without any organic material added to hole, or damage to the tiny rootlets that take up water and trace elements, including iron, from the soil. From a distance, we have no way of diagnosing your tree's problems, nor of recommending a solution. 

To us, the most likely, and simplest answer is that the live oaks are drought deciduous. The live oak is not a true evergreen, but drops all its leaves at once in the Spring, followed quickly by new leaves. Sometimes trees will drop some leaves early to take some of the load off the roots during periods of stress. Don't fertilize any stressed plant. Fertilizer just pushes a plant to put on more leaves, when it is struggling to survive. Unless there is some other problem you didn't mention, we recommend patience. Hopefully, the tree will drop all of it leaves soon, and pop back with fresh new ones.


More Trees Questions

Causes of death to Papershell pinion pine (Pinus remota)?
December 03, 2015 - Good afternoon. I did my best to review the site and have not found a comparable question - apologies if I have missed something. I own property equidistant between Leakey and Campwood off of HWY 33...
view the full question and answer

Eastern red cedar as tall privacy hedge for North Texas
February 28, 2006 - I live in Northern Texas, outside of Dallas, and I need a very, very tall hedge to hide the view of the neighbors car lot from our second floor. We see everything beyond his fence and it drastically ...
view the full question and answer

Replacements for photinia from San Antonio
August 31, 2012 - i just read your response to someone regarding Red Tip shrubs. You just saved me thousands of dollars ! I was getting ready to order over 250 of these to line my 2.5 acre fence line. What shrub would ...
view the full question and answer

Texas Pistachio trees dropping leaves in Austin
June 09, 2010 - I have several Texas Pistachio that are about 13 years old. Despite good rainfall in Travis county this year, they seem to be losing most of their new leaf growth now in early June. Leaves are simpl...
view the full question and answer

Replanting a Desert Willow
February 07, 2016 - My desert willow was damaged badly in a winter storm and had to be taken down. Do I need to remove the old root system below grade when I plant a new desert willow?
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2016 Lady Bird Johnson Wildflower Center