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

Plant identification of fern-like tree in Tennessee/North Carolina
June 17, 2011 - Was on my way to Hilton Head and noticed near the border of Tennessee and North Carolina, there was a tree standing about 4 feet tall. Thin straight trunk and at the very top was fern looking foliage...
view the full question and answer

Small trees for NJ shore
April 22, 2011 - Hello! What's a good native shrub or small tree to feature in my front yard in Brigantine, NJ, on the Jersey shore. Sunny site, dry, sandy soil. The yard is very small. I'm trying to design a l...
view the full question and answer

How close can I plant Mountain Laurels to my house in Austin, TX?
December 08, 2010 - Hello, I'm interested in planting 2 or 3 Texas Mountain Laurels on the side of my house and I'm wondering just how close is safe. I've been told that planting trees too close can damage the slab f...
view the full question and answer

Tree with no invasive roots for Los Angeles
July 24, 2011 - I have a large in ground planter sharing the outside wall (on south/east corner) of my house in east LA 90032. I would like to find a tree that grows quite tall (2 story building), but grows roots ver...
view the full question and answer

Propagating Magnolia grandiflora from Murfreesboro TN
August 03, 2011 - There are several Magnolia grandiflora (Southern magnolia) that have been planted in my neighborhood in middle Tennessee by a landscaping company, and now that they all appear to be producing seeds, ...
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