Native Plants

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?

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 - June 17, 2015

From: Austin, TX
Region: Southwest
Topic: Diseases and Disorders, Trees
Title: Red oak leaves have a swelling along the veins
Answered by: Guy Thompson

QUESTION:

I have red oaks in my back yard, approx 30 or more have a disease that are wilting the leaves. Looking at the back of the leaf there is swelling along the spines. I've gone to one nursery in town that confirmed it was not oak wilt, but had not seen this symptom before. I can send a picture on request. The trees all seem to be fully affected on all branches.

ANSWER:

The disorder of your Quercus texana (Nuttall oak) is caused by the action of a small midge with a name, Macrodiplosis quercusoruca, much longer than itself. It llays its eggs near the leaf vein. Chemicals secreted by the midge's larva as it feeds by the leaf vein cause the tissues by the veins to swell. It seems common in the Austin area this year. I have noticed infested oaks in my yard for the first time. Perhaps the midge prospered because of the unusually wet weather. There is apparently no remedy for this infestation, but I believe that the trees will survive.

Native Plants

Ask Mr. Smarty Plants

rate this answer

Wednesday - June 17, 2015

QUESTION:

ANSWER:

More Trees Questions