Explore Plants

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
    
 

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
1 rating

Wednesday - December 26, 2012

From: San Antonio, TX
Region: Southwest
Topic: Diseases and Disorders, Shrubs
Title: Mountain Laurel slowly dying in San Antonio, TX
Answered by: Jimmy Mills

QUESTION:

My Texas Mountain Laurel seems to be dying in a slow unusual manner. Over the past two weeks the leaves have been turning yellow and falling off starting with the south facing side of my multi-trunk tree and moving to the north facing side. Leaves from all trunks seem to be falling off. About 1/3 to 1/2 of the tree has shed it's leaves. What's more unusual is the newest leaves that grew this past spring seem to be unaffected (so far). But since the tree was heavily attacked last spring by worms, there wasn't much new growth I could save by the time I treated the worms with two separate rounds of BT and Spinosad. Therefore each of the barren branches have only a few inches of green leaves still on them, right at the tips. This tree was transplanted 7 years ago and has done tremendously well (doubling in size to around 12 ft high) until last year when it was attacked by the caterpillars and one of it's trunks died for no apparent reason. It was planted by Millbergers nursery in a raised bed that is also on a slope of a hill so I truly don't believe drainage is an issue. It was on a drip system until the first trunk died and I removed it's emitters in fear that it might have been getting overwatered, while still taking care to make sure it was getting occasional water. No pesticides or roundup of any type has been used near it as well. I also lightly fertilized it this summer with Medina organic granular fertilizer. I can't find anything describing a Texas Mountain Laurel dying in this slow type manner from left to right while keeping (for now) it's newest growth. There are multiple Mountain Laurels in other yards all around me that are doing fine. Obviously the tree is in extreme stress, but my question is do you have any other ideas of what I can possibly do to save what's left of my beautiful tree? Thank you!

ANSWER:


Texas Mountain Laurel Sophora secundiflora (Texas mountain laurel) is often described as being relatively disease and pest free, however it can be attacked by the Genista caterpillar , sometimes referred to as Sophora worms. These two links describe the caterpillars and suggests management  options.

Another common comment about Sophora is that it doesn’t transplant well. You apparently had a six foot sapling transplanted seven years ago, and has so far done well until last year. A question for you to consider is what changed in the plant’s environment at this time? One red flag is your mention of drip irrigation. Sophora is very particular about having its feet wet. Also, fertilizing plants in stress is something we recommend against.

Although the plant was transplanted seven years ago, the symptoms sort of sound like transplant shock. This link  explains causes and remedies for this malady. This answer to a previous  question about a similar situation also has some good advice. The directional nature of your plant’s demise might be explained by the the fact that the south-facing side of the plant is generally getting  more intense sunlight during the day than the north-facing side.  

 

From the Image Gallery


Texas mountain laurel
Sophora secundiflora

More Diseases and Disorders Questions

A year and a half old live oak tree is doing poorly in Nevada, TX.
May 08, 2012 - We planted a live oak tree about a year and a half ago. the tree is still rather small. The leaves are of a vibrant green, however the leave have only grown through the center of the tree and not out...
view the full question and answer

Problems with Monterrey Oak in Austin
March 26, 2013 - We had a local tree service plant two Monterrey Oak trees on 4/2/2012. At the time we noticed that woodpeckers had had a field day on the trunk bark of both trees with the most damage being on the lar...
view the full question and answer

Cool, wet summer effect on evergreen sumac
August 28, 2007 - Hi Mr. Smarty Plants, I have 3 evergreen sumac bushes that I planted as a screen between my house and my neighbors two years ago. They are located in a part of our yard that receives a lot of runof...
view the full question and answer

Fungal root rot in non-native Shasta daisies in Channahon IL
July 21, 2009 - HELP! My Shasta daisies have fungal root rot. Is there any way to save them? I've been removing the browned stems. I'm so sad.
view the full question and answer

Problems with red oak trees in North Central Texas
July 13, 2013 - What is the disease effecting Red Oak trees in North Central Texas; causing them to lose leafs in Spring/Summer and turning the remaining leaves light yellow/lime green in color. Thank you.
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.