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

Friday - May 30, 2008

From: Austin, TX
Region: Southwest
Topic: Pests, Shrubs
Title: Sap drips from Sophora secundiflora
Answered by: Barbara Medford


We have an old Mountain Laurel (sophora secundiflora) about 20 ft tall. It blooms pretty well and seems healthy. We are wondering why it drizzles a non-sticky sap in tiny drops. Hold out your hand and you think it's starting to rain. We hope it's a sign of good health, and we are very curious why the plant does this.


That sounds an awful lot like aphids. Anyone who has ever had to park their car under a tree that has aphids can talk to you about the mess it makes. And every reference to Sophora secundiflora (Texas mountain-laurel) that we found said that it was not threatened by any serious pests and diseases. Don't you hate when they say that and you KNOW there is a problem?

Getting back to the possibility of aphids. The University of California Integrated Pest Management has an excellent website on aphids. In the article, you'll find ways to identify the presence of the little bugs, when they may be more or less numerous, and non-chemical ways to treat them without damaging the beneficial bugs that eat aphids. One note you will particularly appreciate is that aphids do not do well in very hot temperatures. So, since it looks like this is going to be a really hot summer, maybe that's a good thing.

We found another critter that targets Mountain laurel, but is not considered serious except in very young, new trees. The Maricopa (Arizona) County Extension Service has published an article on the Sophora worms, Uresiphita reversalis.



More Pests Questions

Possible freeze damage in Wax Myrtle from last winter in Bastrop, TX
July 25, 2011 - Our Wax Myrtle is about 7 yrs old and in good shape until this past winter when we had several very hard freezes. Now several of the large branches are dead and more are dying each month. We have not ...
view the full question and answer

Groundcover for vineyard from Round Rock, TX
February 04, 2013 - I will be planting a vineyard in the Hill Country next spring. I am looking to maintain low-growing understory plants across the entire vineyard to maintain soil health, choosing plants that the leaf...
view the full question and answer

Failure to bloom of lantanas in San Antonio
July 22, 2010 - Mr. Smarty Plants, We have lantanas in our front yard. This summer the leaves have turned white and they die to a brown color all the while the leaves are "crispy". At the beginning of the season...
view the full question and answer

Discouraging rattlesnakes in northern California
July 12, 2011 - Searching for information re: managing your garden to discourage snakes, especially rattlesnakes. I live in northern California and we have many. I found one of your articles, but the link to an U. of...
view the full question and answer

Puppy-proof plants in Denton TX
June 04, 2010 - I recently got a couple of puppies that stay outside in a fenced off area of the backyard. Of course, they love trying to dig under the fence and get out. I placed cement landscaping border stones alo...
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.
© 2015 Lady Bird Johnson Wildflower Center