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?


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 - July 30, 2012

From: Austin, TX
Region: Southwest
Topic: Pests, Trees
Title: Something dripping from red oak in Austin
Answered by: Barbara Medford


There is a large red oak outside my apartment. The leaves are shiny and covered with what appears to be oil. The ground underneath is coated with this also. When I parked under the tree my car became covered with oil. It came off easily at the carwash. I don't see any bees or insects and the tree appears healthy. It could be sap, except that it seems to be coming from the leaves. My main concern is that this is possibly an insect infestation.


Because we are hearing about so much dripping from trees, frequently from oaks, that we are going to take a chance and send you links to some previous answers. It seems to be an absolute epidemic in Austin this year, possibly because of the weird weather.

Austin, July 14, 2012

Boca Raton, FL July 10, 2012

These were just the most recent on the subject. We have about 100 questions on aphids in our previous Mr. Smarty Plants questions.

Since this oak is apparently on the grounds at your apartment, you should probably alert the management to have their garden maintenance people examine it. Emphasize, NO HERBICIDE! The herbicide will kill beneficials (like lady bugs) that feed on the aphids and not faze the aphid eggs waiting to hatch into more aphids.


More Trees Questions

Hiring a landscaper in New Jersey
July 28, 2008 - Soon I will be hiring a landscaper to plant a privacy line of arborvitaes with a 1' retention wall and I need some help on prices. The quote I was given, which included 48 arborvitaes (and I will ac...
view the full question and answer

Tree (evergreen) to grow in area with high water table
March 27, 2011 - Dear Mr. Smarty Plants, We live in central Austin, Tarrytown specifically, just blocks from the aptly named Spring Lane. (sometimes we hit water in our back yard within 2 feet of the surface.) We los...
view the full question and answer

Trimming a bur oak in Llano, TX
February 06, 2009 - We have a beautiful, large Burr Oak next to our house. This tree has many large lateral branches. I have trimmed dead branches, but no other trimming. It grows a lot of "suckers" during growing sea...
view the full question and answer

Puppy-friendly privacy screen in Montana
November 02, 2012 - I need some puppy-friendly short(< 30') privacy from the gigantic windows of my next door neighbor. But- there are power lines above the area that I needed to plant! I had planned on an aspen grove, ...
view the full question and answer

Juniper as host of cedar-apple rust
July 17, 2007 - Thanks for the helpful advice on the Eastern Red Cedar. I was wondering if you could ease my mind about a potential problem. I have read up on some of the native plants in my area in a very good book ...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2015 Lady Bird Johnson Wildflower Center