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
Not Yet Rated

Friday - November 22, 2013

From: Dallas, TX
Region: Southwest
Topic: Diseases and Disorders, Trees
Title: Is post oak resistant to oak wilt from Dallas TX
Answered by: Barbara Medford

QUESTION:

I am confused. The NPIN website says that Post Oak IS susceptible to oak wilt, but all the other information I have been able to find says that it is resistant to oak wilt and rarely gets the diesase. Can you tell me where the information on the NPIN website originates from or if perhaps it is an error?

ANSWER:

Don't feel alone. The facts on Oak Wilt are confusing to everyone. We did find the line on our wepage for Quercus stellata (Post oak) that you mentioned:

"Susceptible to oak wilt. Not often used in landscape situations. Slow-growing and long-lived." The Post Oak is a White Oak.

We will go to another source, texasoakwilt.org, for some clarification, if possible. We suggest you scan the whole site. From the Introduction to that site: "All oaks (Quercus spp.) are susceptible to oak wilt to some degree, but some species are affected more than others." Also from that website:

"Patterns of Tree Mortality

 Most live oaks defoliate and die over a 1- to 6-month period following initial appearance of symptoms. Some live oaks take longer to die, and a few untreated trees may survive many years in various stages of decline. Occasionally, a few live oaks in an oak wilt center may escape infection and remain unaffected by the disease.

Red oaks never survive oak wilt and often die within 3 to 4 weeks following the initial appearance of symptoms. During summer months, diseased red oaks often can be spotted from a distance because of their bright autumn-like coloration in contrast to the surrounding greenery."

From the Texas A&M Forest Service, here is a map of the counties in which oak wilt appears in Texas. Also from that site:

"Oak wilt has been found in over 73 counties and in almost every city in Central Texas, as well as, Abilene, Midland, Lubbock, Dallas, Ft. Worth, College Station, Houston, and San Antonio. It can be a problem wherever live oaks tend to be the predominate tree. It does not matter whether they are transplanted or naturally grown. An individual tree’s age, size or previous health status does not make it more

"Red oaks, particularly Spanish oak (Quercus buckleyi), are very susceptible to the fungus.  White oaks, like post oak (Q. stellata) and bur oak (Q. macrocarpa), are resistant to the fungus and rarely die from the disease."

Bottom line: If you want to add oaks to your landscape, a post oak is probably less  likely than the red oaks and live oaks to contract Oak Wilt. If you choose the post oak or have some on your property that you wish to protect, you should still follow the management policies from the Management section of texasoakwilt.org.

 

From the Image Gallery


Coastal live oak
Quercus virginiana

Coastal live oak
Quercus virginiana

Texas red oak
Quercus buckleyi

Texas red oak
Quercus buckleyi

Post oak
Quercus stellata

Post oak
Quercus stellata

More Trees Questions

Are poplar trees and willows safe for animals to eat
August 04, 2008 - poplar trees and willows, are they friendly for farm animals to consume leaves?
view the full question and answer

Live oak leaves not dropping from Austin
April 29, 2014 - We had a 65 gallon live oak planted last October. We watered it regularly and it was green all through the winter. In March the leaves started to turn brown but never dropped, as they should have. ...
view the full question and answer

Problem with crapemyrtle shoots in Victoria, TX
May 13, 2009 - I have a problem with crepe myrtle shoots coming up in my flowerbed. I had to remove a large crepe myrtle tree (18" diameter stump) and digging out the stump was not possible. I killed the stump wi...
view the full question and answer

Are Eastern White Pine suitable for Waxhaw NC
February 13, 2011 - Pinus strobus ( White Pine )- I wish to plant four of these evergreens along our property lines as a screen. Our county is selling one foot plants in a container. Our soil is clay. Are these t...
view the full question and answer

Propagating a Magnolia tree from a twig cutting in New Hampshire.
November 02, 2011 - I have a twig cutting from a rare magnolia tree I found on a farm in central New Hampshire. The tree seems to be at least one hundred years old. It was in full bloom in late August and I was told by t...
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