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?

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
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

Problems with Texas Ash in Cibolo TX
May 14, 2010 - I have a Texas Ash tree I planted two years ago. The tree was 10 feet high with thick foliage. This spring the leaves started falling off after I spread fertilizer on my yard. The end of the branches ...
view the full question and answer

Are Ashe Junipers dying from mite damage in Austin?
August 08, 2011 - If Ashe Juniper needles are turning brown and dropping off the trees because of drought, and not disease, do the needles ever come back, or have the tree limbs died? What if the cause is mites, not ...
view the full question and answer

Rhododendrons Hydrangeas in Indiana
December 13, 2007 - I live in very southern Indiana. Our home faces west and at the front of our home I have planted three rhododendrons. The furthest south is growing well the two to the north not so well. All three h...
view the full question and answer

Rock under space for Bigtooth Maple in San Antonio
May 20, 2013 - I just got a 10 gallon Bigtooth Maple in Medina TX for my home outside loop 1604 in San Antonio. I hit rock about 7 inches in when trying to plant it..I am entertaining the idea for a raised bed to le...
view the full question and answer

Trees for privacy in NY
March 17, 2011 - I am looking for trees native to New York that I can plant in front of my backyard fence that is six feet tall that will not hide my fence or overshadow my east facing garden beds and plants underneat...
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.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center