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
Not Yet Rated

Thursday - September 23, 2010

From: San Marcos, TX
Region: Southwest
Topic: Diseases and Disorders
Title: Sooty mold on Sophora secundiflora in San Marcos, TX.
Answered by: Jimmy Mills

QUESTION:

Dear Mr. SP, We have a Sophora secundiflora that is suffering with very black mold or fungus on most of its leaves. Last year, I washed it leaf-by-leaf with soapy water but it's getting too big to continue that. The tree right next to it shows no sign of the problem. The cover is so thick that the tree, except for new growth, looks black. Any suggestions?

ANSWER:

What you are experiencing is an attack of sooty mold on your your Mountain Laurel. The sooty mold is a fungus, and while it  isn't particularly harmful to your plant, it is unsightly. The fungus is growing on honey dew which is a sticky substance that is being excreted by aphids or other scale insects as they feed on your plants. Since the aphids are so small, they are often not noticed until the sooty molds tips you off to their presence. If the sooty mold becomes thick enough, it can prevent leaves from receiving adequate sunlight.

Here are three sources of information about this problem. The University of California at Davis Integrated Pest Management Program has two good articles; one on sooty mold, and one on aphids. This article from the USDA tells how to recognize and control sooty mold.

 

 

 

More Diseases and Disorders Questions

Beautyberry Dying Back
August 06, 2015 - I've got an American Beautyberry which I planted in the spring. It's now about 2-3 feet tall and has 3 trunks (or limbs). It's in an area which gets about 5 hours of direct sun per day and I've be...
view the full question and answer

Strange growth on oak tree
August 26, 2008 - 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 st...
view the full question and answer

Can a Quaking aspen grow in central Texas?
August 11, 2015 - I live in Austin and like the idea of a Quaking Aspen tree. I live on a creek and the tree(s) would get good sun and water. Am I crazy?
view the full question and answer

Young pecan trees with leaf and branch problems from Gatesville TX
November 18, 2013 - I have a young pecan tree that had very rapidly browning Leaves. They became brittle and so did the branches with affected leaves. The branches soon fell off. We treated with fungicide during that pro...
view the full question and answer

Pest on leaves of native Texas persimmon in Laredo, TX
February 20, 2009 - I have a transplanted a Texas persimmon tree from the wild. It has some globes in the leaves. It seems like some pest injected something from underside of leaves. Any suggestion? What is happening t...
view the full question and answer

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