En EspaŅol

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
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
Need help with plant identification, visit the plant identification page.
 
rate this answer
1 rating

Wednesday - September 21, 2011

From: Abilene, TX
Region: Southwest
Topic: Diseases and Disorders, Trees
Title: Live oak trees with rusty spots and holes on tree trunks
Answered by: Nan Hampton

QUESTION:

I have live oak trees that have developed rusty spots, small holes on the tree trunks and sawdust on the trees base. They were planted in Oct 2010. We have had a hot dry summer in Texas this year and I am not sure if this is due to the extreme hot weather. Please advise.

ANSWER:

The principal disease associated with Quercus fusiformis (Escarpment live oak) is oak wilt.   As you can read on the species page on our Native Plant Database:

"...it is susceptible to live oak wilt and live oak decline when stressed by drought, so care must be taken to protect it from injury both aboveground and below ground to prevent infection."

Certainly, your trees have experienced the stress of extreme drought and high temperatures. I don't know if your trees are infected by oak wilt, but it is certainly possible.  You can see on this map from the Texas Oak Wilt webpage that Taylor County has been confirmed as having oak wilt.  You can see the characteristic leaf browning pattern associated with Texas oak wilt on the Texas Oak Wilt Information Partnership page. Contact the Taylor County Office of the Texas AgriLife Extension Service to see if you can arrange to have someone look at your trees to determine if you do have oak wilt.  You could also consult a professional arborist.  You can search for a Certified Arborist in Abilene on the International Society of Arboriculture page. The Texas Oak Wilt Information Partnership page has a wealth of information about diagnosing, treating and preventing oak wilt.

Another disease that can affect oak leaves is Tubakia (formerly known as Actinopelte) but it is usually a disease associated with wet years which certainly doesn't apply to this year.  For insect pests, you can read Insect Pests of Central Texas Forests to learn that nitidulid beetles are responsible for spreading the fungus, Ceratocystis fagacearum, that causes oak wilt and that stressed trees are often attacked by wood borer insects and oak bark beetles. 

Whatever you trees are suffering from, there is no doubt that they have been seriously stressed by the heat and drought conditions.  You might also read "Continuing Severe Drought Conditions Will Seriously Harm Trees" from the Texas Forest Service.

 

More Diseases and Disorders Questions

Problems with gnats in dirt
December 27, 2008 - I have problems with gnats in my dirt. It's something I can't get control of. What can I do?
view the full question and answer

Disease-resistant squash varieties for Central Texas
February 03, 2008 - Can you give me names of some disease-resistant summer squash varieties available in Central Texas?
view the full question and answer

Willow woes in Philadelphia, NY
August 22, 2010 - I have a 2 yr old willow; it is August and it looks like the tree has gone dormant, is this normal?
view the full question and answer

Leaves browning on non-native willow from in Cumbla PA
July 10, 2011 - We recently planted a willow tree. A lot of the leaves turned yellow and some turned brown, but it is also getting some new buds. my question is, should I take the dead leaves off or leave them there...
view the full question and answer

Failure to bloom of Campsis radicans in Elkins WV
June 28, 2011 - Dear Mr. Smarty Plants, We live in a very cool climate of West Virginia, in the mountains, and it seems impossible for our Campsis radicans vines to flower! Perhaps the growing season is too short? W...
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center