En Español

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
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

Non-native crape myrtles in Noblesville IN
August 01, 2012 - Can Crepe Myrtle trees be grown in Noblesville IN 46060? I believe we are zone five.
view the full question and answer

Desert Willow and Orchid tree with no upper leaves from Kerrville TX
May 30, 2013 - I have two 5 year old Desert Willows planted in my yard. This year only one has leaved out and blooming. The other is bare but the branches are not dead and it has new growth at the bottom. Do you kno...
view the full question and answer

How can I tell the age of a Pecan tree in Rosenberg, TX?
September 03, 2010 - How can I tell the age of a Pecan tree? I live on the Brazos River and have a lot of large Pecan trees but the largest is approx. 11 ft. around.
view the full question and answer

Difficulty with Clay Soil from Palm Bay, FL
August 22, 2012 - I had a very nice little native shady area behind my house for over 40 years, but now it has been cleared except for a 100 foot tall live oak in the center of this raised mound (50' x 80'). I've be...
view the full question and answer

Deciduous shade tree for Inland California dry hills
July 26, 2011 - What type of tree would work well in our back yard? We're looking for a deciduous tree that doesn't grow too tall, maybe 20'. We'd like it to have spreading branches to provide shade during the su...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | JOBS | SITEMAP | STAFF INTRANET
© 2016 Lady Bird Johnson Wildflower Center