Native Plants
![](../_images/smarty_plants.gif)
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.
Did you know you can access the Native Plant Information Network with your web-enabled smartphone?
Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.
![](../_images/mr_smarty_plants_logo_web_200w.jpg)
rate this answer
![](../_images/star_43.gif)
Friday - October 19, 2012
From: Houston, TX
Region: Southwest
Topic: Pests, Trees
Title: Are fuzzy oak leaf galls harmful to post oak trees?
Answered by: Nan Hampton
QUESTION:
Are the fuzzy balls on the undersides of our post oak trees harmful?ANSWER:
The fuzzy balls are galls formed by the tree leaf in response to the feeding of the larvae hatched from an egg deposited by a tiny gall wasp in the Family Cynipidae, Genus Andricus. Here are photos of Andricus quercusflocci galls that form on leaves of Quercus alba (white oak) and Quercus prinus (chestnut oak). Andricus pattoni is reported to be the species that lays eggs on postoaks, but I could find no photos for that species of gall wasp. Here is a link to an article about other Oak Cynipid Galls from the Department of Entomology, University of Minnesota. You can see other types of galls in this article from the University of Wisconsin-Milwaukee and here is more information and photos from the University of Pennsylvania. Here is a link to an article on Randy Lemmon's Gardenline on KTRH radio about galls on oak trees in Houston in 2010.
In general, the galls are not harmful to the trees and there is really no insecticide that is effective since the wasps are tiny and not easily seen, plus the larvae are well-protected from pesticides within the galls. Additionally, insecticides applied are very likely to be harmful to beneficial insects.
More Trees Questions
Native cherry trees for Georgia
July 06, 2007 - Is it possible to grow any type of cherry in Georgia, USA?
view the full question and answer
Is bald cypress native to Dallas area?
September 19, 2009 - There are 2 very large bald cypress trees growing beside one another at a park in North Dallas, and I was wondering if they were native or planted a long time ago by the settlers or something. They ar...
view the full question and answer
Illegal to remove an orange blossom from ground in Florida from Atlantis FL
March 28, 2012 - Is there any law that prevents someone from removing an orange blossom from the ground in Florida?
view the full question and answer
Problems with Eastern hemlock in Greenville SC
July 02, 2009 - Dear Mr. Smarty Plants,
I have a beautiful, young, 5 and a half foot tall Eastern Hemlock. I purchased and planted it two years ago in the fall. It has been doing very well all this spring. And ne...
view the full question and answer
Over-trimming of native linden tree
November 06, 2008 - Dear Mr. Smarty Plants, My huge beautiful linden tree was just way over trimmed. It is planted near the house, so they cut most of the branches on that side all the way back to the trunk. I now have...
view the full question and answer
Support the Wildflower Center by Donating Online or Becoming a Member today. |