Host an Event Volunteer Join Tickets

Support the plant database you love!

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
Not Yet Rated

Thursday - July 04, 2013

From: Katy, TX
Region: Southwest
Topic: Diseases and Disorders, Trees
Title: Chlorotic disease in scrub oak from Katy TX
Answered by: Barbara Medford

QUESTION:

Please tell me how to treat my scrub oak as it has chlorotic disease. Parts of the tree are fine and others have yellow leaves. It has not been injured in any way.

ANSWER:

There are four plants native to North America with the common name "scrub oak." The map link following each plant name refers to the USDA Plant Profile Map on that plant showing to what states it is native. In the case of the two native to Texas, the map indicates the Texas counties in which a scrub oak grows natively.

Quercus dumosa (Coastal sage scrub oak) - endemic (growing natively nowhere else) to California (Map)

Quercus ilicifolia (Bear oak) Also known as  Scrub Oak (Map). Not reported as growing natively in Southwest U.S. at all.

Quercus mohriana (Mohr oak)  Also known as shin oak, scrub oak. (Map) West Texas and Panhandle.

Quercus turbinella (Sonoran scrub oak) (Map) El Paso, Hudspeth and Brewster Counties in Big Bend Area of far West Texas.

None of these sound very likely to be garden plants in Harris, Ft. Bend and Waller Counties, in southeast Texas. Is it possible that you got the wrong common name? As long as it is a member of the Quercus (oak) genus, it probably doesn't matter. Chlorosis in the Quercus genus is usually a product of being grown in incompatible soils.

Please read this previous Mr. Smarty Plants answer on chlorosis in another species of oak, Quercus palustris (Pin oak). We hope this helps you establish what your tree is and the best ways to deal with chlorosis.

 

From the Image Gallery


Coastal sage scrub oak
Quercus dumosa

Mohr oak
Quercus mohriana

More Diseases and Disorders Questions

Cutting Back Perennials in the Fall?
November 13, 2013 - We have large beds of flowering native perennials that we planted around our house as part of a landscape conservation plan (various Joe-Pyes, goldenrods, turtlehead, blazing star, brown-eyed Susans)....
view the full question and answer

Why isn't my recently planted Mexican Redbud growing in Georgetown, TX?
April 11, 2010 - I planted a container-grown Mexican Redbud in early March. As of April 5th, it is showing no signs of buds or leaves. Other redbuds in the area (possibly Texas redbuds) have been blooming for severa...
view the full question and answer

Spots on non-native naval orange trees from Stockton CA
October 20, 2012 - I have two mature Navel Orange trees. One tree has developed spotty chlorophyl depleted areas that were not on the oranges when they were smaller. In addition, the oranges on both trees are smaller ,...
view the full question and answer

New growth on Amur Maple turning black in McPherson, Kansas.
June 29, 2010 - Re: Amur Maple bushes Approximately 2 yrs old, 4 ft tall. New growth at the end of some branches is turning black. Plants are mulched with grass clippings. We live in Kansas. Thanks for any info....
view the full question and answer

Bulging trunks on post oak
August 05, 2011 - I have a huge post oak with a codominant trunk that is bulging between the two main trunks. The bulging is causing the trunks to spread apart, so one of the trunks is getting much too close to the ho...
view the full question and answer

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