Host an Event Volunteer Join Tickets

Support the plant database you love!

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
2 ratings

Tuesday - August 26, 2008

From: Grafton, MA
Region: Northeast
Topic: Diseases and Disorders
Title: Strange growth on oak tree
Answered by: Nan Hampton

QUESTION:

i have a very strange round segmented growth on a tree in my yard. i think the tree is a chinkapin oak and the growth is a reddish color. it looks like a ball with suction cups on it. it is very strange looking thing and I have not been able to id it anywhere!

ANSWER:

It sounds as if your tree has a gall.  This is a growth that the tree makes in response to an insect or another organism such as a mite or a fungus.  Many galls are caused by an insect laying its eggs in the tree.  The insect hatches inside the gall growth, feeds on the growth and then emerges from the gall to continue its life cycle.  Here is more information about oak galls from the University of Kentucky and here is a Gallery of Common Galls from North Carolina State University.  Your growth sounds a bit like a horned oak gall.  If you don't find your growth in one of these links, please send us a photo and we will do our best to identify it.  Please visit the Ask Mr. Smarty Plants Plant Identification page to read instructions for submitting photos.

Note from Mr. SP:  After this answer was posted, someone else sent us a photograph that sounds very much like the gall described above.  We submitted the photo to BugGuide.net and asked if anyone could identify it.  Someone did identify it as being made by a gall wasp, Adleria quercusstrobilana, in the (Family Cynipidae), laying its eggs in the stem of the tree.

 

More Diseases and Disorders Questions

Yellowing of fronds on Sago Palm
March 27, 2007 - Our Sago Palm now has all yellow fronds from the Winter frosts. Should they be cut off? Will the plant grow new fronds from the bottom to replace the ugly looking ones that are there? And why do I se...
view the full question and answer

Smarty Plants on Oleanders
June 11, 2005 - I have 3 Nerium Oleanders. In the winter they come indoors, and are under grow lights. They are in big pots. We just put them outside on patio, and they don't look good. They still have green tips ...
view the full question and answer

Large oak with possible Laetiporus fungus
November 29, 2011 - We have a huge oak tree in front of our new house. After the first rain this fall a large fungal growth appeared in an old knothole of the tree and I would guess that it is Laetiporus. A neighborho...
view the full question and answer

Why are my Spanish Oaks dropping branches that appear to be alive?
June 24, 2009 - We have two large Spanish Oaks that we planted ourselves. They both have begun to loose large branches that aren't dead. These branches just break off and fall. There is usually a wind, but not to th...
view the full question and answer

Yellow in pin oak leaves from Allen TX
May 25, 2012 - I have two pin oaks and one is completely yellow - a sign of iron deficiency and the other is starting to turn completely yellow as well. I've a proposal for iron deficiency but it is quite expensiv...
view the full question and answer

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