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

Monday - April 01, 2013

From: Katy, TX
Region: Southwest
Topic: Diseases and Disorders, Pests, Trees
Title: Growths on Shumard Red Oak leaves from Katy TX
Answered by: Barbara Medford

QUESTION:

Our beautiful Shumard Red Oak has developed lots of light green grape like growths on the leaves. Please inform us what this could be and how we should treat it?

ANSWER:

Quercus shumardii (Shumard oak) is, according to this USDA Plant Profile Map, native to Harris and Ft. Bend Counties, which means it is growing in the right place.

We learned in this article from Cornell University, Department of Plant Pathology that Quercus shumardii (Shumard oak) can develop oakleaf blister. This is a fungus and red oaks (which the Shumard Oak is) can be most susceptible to it. The pictures in that article don't look much like what you are describing so we will look further.  From Texas A&M AgriLIFE Extension, Texas Plant Disease Diagnostic Lab here is an article on Oakleaf Blister

Insects that attack the Shumard Oak are June beetles, striped oakworms. cankerworms, forest tent caterpillars, yellow-necked caterpillars, variable oakleaf caterpillars and red-hum[ed oakworms. Shumard oak acorns are subject to attack by acorn weevils. If you suspect any of these, you can search on the Internet for any of them for pictures and more information.

However, we suspect oaks galls. Here is an article from the University of Kentucky Extension Service on Oak Galls. It has no pictures at all, so we will try to find more information. From Google, we found Images of Leaf Galls, some of which look very like what you are describing. If you click on one of those pictures it will show you an enlargement, and if you click on it again, it will take you to the website from which the picture was copied.

Since we are neither entomologists nor plant pathologists, we suggest you consult a trained, licensed arborist for what to do next. It could be that, though unsightly, the problem is no serious threat to the tree.

 

From the Image Gallery


Shumard oak
Quercus shumardii

Shumard oak
Quercus shumardii

More Diseases and Disorders Questions

Insects attacking Gregg's Blue Mistflower from Comfort TX
June 20, 2013 - I have a beautiful stand of Gregg's Blue Mist flower that have been attacked by an unknown insect. The new growth is curled and stunted and it is not flowering. I'm not alone..I've seen the Gregg'...
view the full question and answer

White fuzz on Christmas tree from Lewisburg PA
January 04, 2011 - Our Canaan fir Christmas tree is now coated with white fuzz after being up for 4 weeks. The fuzz looks like spider webs, but it is also in clumps around the needles. When you rub your finger on it, ...
view the full question and answer

Desert Willow and Orchid tree with no upper leaves from Kerrville TX
May 30, 2013 - I have two 5 year old Desert Willows planted in my yard. This year only one has leaved out and blooming. The other is bare but the branches are not dead and it has new growth at the bottom. Do you kno...
view the full question and answer

Failure to thrive of trees in Savage MN
August 23, 2009 - I have a 20+ year old weeping willow. The last few years it is the last tree to get its leaves and the first to lose them. The few leaves that are still on the tree are covered with brown/black spots....
view the full question and answer

Problems with yaupon from San Angelo TX
April 08, 2012 - We have a 3-yr-old yaupon holly entering its 3rd summer. We have put store-bought wood-chips under the tree several times since it was planted. A plant has grown under the tree, possibly out of the ...
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