Rent Shop Volunteer Join

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
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

QUESTION:

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?

ANSWER:

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 Diseases and Disorders Questions

Possible freeze damage to Texas Persimmon in Fair Oaks Ranch TX
June 27, 2010 - I have a Texas Persimmon tree that is in a green belt. It has leafed out and flowered for the eight years we have lived here. This year it leafed out then the leaves turned brown and dropped. The top ...
view the full question and answer

Failure to thrive of pecan trees in Las Vegas NV
October 11, 2009 - In April this year I purchased two 8-foot tall pecan trees in 3-foot square boxes from a local nursery and planted them here in Southern Nevada. I'm sure I dug a large enough hole to provide plenty ...
view the full question and answer

Allelopathy of American elms from Dallas
March 24, 2013 - Are American elms at all allelopathic?
view the full question and answer

Drought-resistant and grub-resistant grass for Smithville TX
October 02, 2012 - I want a drought resistant grass for a sunny area that is also resistant to grubs. I have lots of grubs but want a healthy soil of good microbes. Any ideas? Zoysia, Buffalo? I noticed that Tech Turf r...
view the full question and answer

Swarming insects on non-native willow in Washington PA
September 25, 2011 - I have had a very large, beautiful pillow willow bush/tree growing next to our garage for about 8 years. Last year at the end of August, it began to attract white-faced hornets and yellow jackets by t...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.