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 - September 05, 2008

From: Plano, TX
Region: Southwest
Topic: Trees
Title: Bur oak defoliation
Answered by: Joe Marcus

QUESTION:

I have a bur oak that was planted in 1993. In 2000, I had mortared stone edging (approx 5 inches deep) installed around the trunk from 4 to 6 feet away. In the last 3 years, the tree seems to be declining (early defoliation, almost dead leaves on one side at the top, khaki-colored foliage in July). I am willing to remove the edging if it will help. My questions are these: 1) Do you think the edging is the problem? 2)If it is removed, will the tree roots grow out or have I created a bowl where the roots will continue to grow circularly?

ANSWER:

The mortared edging you installed eight years has almost certainly had no part in creating on the condtion you've described.  However, we are not sure just what is causing the problem.  Well-established bur oaks rarely suffer from diseases, those they are notably susceptible to cotton root rot (Phymatotrichum omnivorum) and Strumella canker (Strumella corymeoidea).  Cotton root rot is a particulary common problem in your area in North Texas.  The most common and troublesome oak disease in Texas, Oak Wilt, does not often affect bur oaks, though it can and does occasionally.  Finally, various insects and mites can attack bur oak foliage, disfiguring and even killing the affected leaves.

Environmental changes in the root zone can cause tree defoliation and decline.  If you have made any major changes to the soil within the root zone of the tree - especially changes in watering, herbicide applications, any trenching, or any changes in soil depth in the last couple of years, those changes could be the cause. 

It would be best to have a certified arborist examine your tree to help you determine just what is causing the symptoms you're seeing. 

 

More Trees Questions

Flying insects eating leaves of non-native Brugmansia in Aline CA
October 17, 2013 - I have an Angel Trumpet tree. We live in Aline, California 30 miles east of San Diego. Little yellow and black flying bugs eat the leaves. Do you have a remedy for this problem.
view the full question and answer

Propagation of redbuds from shoots in St. Louis MO
July 17, 2009 - I have a beautiful, healthy old redbud tree that I love. Every year, I find baby redbud trees rooted all over my yard, Since they are deep, I can't seem to dig them out so I simply cut them down to...
view the full question and answer

Nut tree for Florida
October 09, 2008 - Hi! I would like to plant a nut tree in Orlando, FL. What would you recommend?
view the full question and answer

Evergreen sumacs for privacy along fence
August 02, 2014 - I would like to plant enough Evergreen Sumacs along our fence for privacy for the length of our backyard which is 60 ft. Fifteen feet on the left and right ends are shaded with the right side being d...
view the full question and answer

Adjustments to soil level change around tree from Austin
May 29, 2014 - I am moving in to a new construction home in south Austin, builder has leveled the ground and sodded the front yard, I have a post oak in the front and because of the changes to the landscape the tree...
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 | STAFF
© 2015 Lady Bird Johnson Wildflower Center