Rent Shop Volunteer Join

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

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

Wednesday - April 04, 2012

From: Austin, TX
Region: Southwest
Topic: Diseases and Disorders, Pruning, Trees
Title: Red oaks that didn't drop leaves in Austin
Answered by: Barbara Medford

QUESTION:

I have a number of Red Oaks on land that did not drop leaves this past fall. Now these same trees seem to be dead? It seems there's some type of mold/fungus on the trees. Some trees have small patches of this stuff while others have it up and down the whole trunk. If I cut the trees down will it spread? Is it bad, should I worry? Anything help?

ANSWER:

A group of volunteers at the Lady Bird Johnson Wildflower tree were looking at  Quercus buckleyi (Texas red oak) on the grounds of the Center. It also had not lost its leaves, which were quite brown. Damon Waitt, the Senior Botanist, did the "thumbnail" test, scratching a very thin sliver of bark off a large limb, and found a layer of green beneath it, which indicated the tree was still alive. The stems were also limber. The conclusion was that the tree would probably survive. Even though the Wildflower Center does do some irrigation, we were limited, like everyone else in Austin, to as little as possible last year, and as you know, it did not rain. Now, of course, some things we thought were dead, shrubs, trees, etc. are popping leaves out and carrying on. Hopefully, so will your tree. In fact, more recently, we passed that tree and it is leafing out like crazy.

However, (isn't there always a "however"?) the description of the fungi on your tree trunks is pretty alarming. Oak Wilt, a scourge of red oaks, is a fungus transported by the nitiludid beetle. A wound in the bark, as from an unpainted pruning scar or damage from a weedeater or lawnmower, will exude a sap, which is ambrosia to the beetle. If he has been feeding somewhere else in oak sap, perhaps from a tree already infected by Oak Wilt, the fungus spores will infect the new tree.

Since we are not plant pathologists and certainly couldn't diagnose this problem sight unseen, we want to refer you to a website that should be able to help you. First of all, you are going to need professional help from a trained, licensed arborist. The Texas Oak Wilt Partnership, in which the Lady Bird Johnson Wildflower Center is an active partner, should be looked at closely. Under "Getting Help" you will find out you are in the Austin District, and get names and contact information on Oak Wilt specialists.

This is the time of year when the nitiludid beetle, spreader of Oak Wilt, is most active, so if the tree is infected, you will need to take the advice of the expert you bring in on whether to cut it down now or wait until the dormant months of December and January and also on how to protect other oak trees in the vicinity.

 

From the Image Gallery


Texas red oak
Quercus buckleyi

Texas red oak
Quercus buckleyi

More Trees Questions

Trees to hide telephone poles and wires
September 28, 2009 - I am looking for trees to plant between my house and the street to hide telephone poles and wires. My top priority is to add strong, gold color in the fall. Spring flowers would be a plus. Because ...
view the full question and answer

Brown spots on young redbuds in Lincoln TX
August 01, 2010 - I have lined my driveway in Lee County Texas with Red bud trees purchased both in Dripping Springs and in College Station. The 14 trees are of varying ages and heights (planted during the fall and wi...
view the full question and answer

Native flowering aromatic trees for Frisco, Texas
June 21, 2015 - Dear Smartplants, I live in Frisco, Texas. Could you please suggest me good native flowering aromatic trees from 12 to 50 feet. Thank you so much
view the full question and answer

Transplanting crabapples in NJ
October 25, 2010 - I purchased a mature Red Baron crabapple in march of this year from a reputable nursery here in southern NJ. The tree was in the ground when I first viewed it, and since it was march and hadn't bloom...
view the full question and answer

Yucca rostrata needs some help in Austin, TX.
September 16, 2013 - We planted an expensive 5-6 foot Yucca rostrata last fall. It bloomed beautifully in the spring. We installed an irrigation link to water the recently planted areas with succulents, viburnums, spart...
view the full question and answer

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