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

Saturday - April 19, 2008

From: Austin, TX
Region: Southwest
Topic: Trees
Title: Problems with sophora secundiflora
Answered by: Barbara Medford

QUESTION:

My mountain laurel is looking bad. It has lost of its leaves, especially on the lower part of the tree (it's about 7 feet tall) and many of the remaining ones don't look good - they are curled up and spotted. The spots could be from insect eggs. This is the second year this has happened. It continues to get healthy new growth, however, and it bloomed some this year. I planted it about 20 years ago. It gets full sun. Several other mountain laurels close to it are perfectly healthy. Is this some kind of insect infestation? What should I do to care for it?

ANSWER:

The first possibility is that the leaves are chlorotic; that is, they don't have enough chlorophyll, which can cause black spotting between veins in the leaves. Plants can become chlorotic because the soil in which they are growing is so alkaline that the plant has difficulty extracting the iron that it needs from the soil. In the Austin area, particularly with other mountain laurels growing nearby, it seems unlikely that too much alkalinity is the problem. However, chlorosis in the Sophora secundiflora can also be caused by overwatering or watering too shallowly. This particular plant requires very good drainage and is accustomed to growing on limestone shelves or in very rocky soil. If your affected mountain laurel is in a low spot, a spot that accumulates moisture from runoff, or is watered by a sprinkler system, but not thoroughly, that could be causing the symptoms you are observing. Check the drainage on that tree; they need only be watered (if there has been no rain) every two to four weeks, but need to be deeply and thoroughly watered then. We think this is probably the most likely culprit.

We found several references to the genista caterpillar, apparently the larval stage of the Genista moth. Read this article on the Sophora Worm from the Maricopa (AZ) County cooperative Extension Home Horticulture site and see if any of the symptoms match the ones you are observing. Apparently, just picking off the caterpillars and/or destroying the webs that are spun by them controls that problem. If, upon close examination, you feel this is your problem, the website says you probably don't need to worry about it, but does give suggestions for control if the problem becomes severe.

 

 

More Trees Questions

Are red berries of modesto ash toxic to dogs
November 29, 2010 - Are the red berries that come off the modesto ash tree poisonous to dogs if they eat them?
view the full question and answer

Need help with my 25 yr old Mountain Ash in Clinton Township, MI.
July 11, 2011 - For the first time our 25yr old mountain ash tree has dying branches, we removed one branch and it seems to have spread to other branches? What should we do?
view the full question and answer

Dying trees in San Marcos, Texas
September 24, 2011 - I live on 11 acres in San Marcos and cannot water at all during this drought. All of my oaks and mountain laurels are turning brown. Does this mean they are all dying? Will they come back in the sp...
view the full question and answer

Failure to thrive of Eastern Redbud in Dearborn, MI
May 26, 2009 - Our Eastern Redbud, multi-stem tree has done well for several years. This year the pods did not fall off, the tree looks anemic, lots of dead stems, no pink blooms this spring. What can we do??
view the full question and answer

Leaves falling off recently transplanted mature Mountain Laurel
July 05, 2006 - I have recently purchased a Mountain Laurel for my backyard landscaping. It is a fully matured ML standing over 9 feet tall by 6 feet wide. Since it was planted (about 6 weeks ago) it has been losin...
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.