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?


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
4 ratings

Thursday - August 31, 2006

From: Helotes, TX
Region: Southwest
Topic: Trees
Title: Possible wilt disease in mountain laurels
Answered by: Joe Marcus


Three of about 24 of my mature mountain laurels died suddenly, the leaves turned brown almost overnight, scratching the bark revealed no green tissue, the small branches practically cracked when bent, the leaves went from green and healthy to dry and brown in about three to four days, the plant seemed to have just dried up. I do not believe they were over or under irrigated as other healthy mountain laurels remain immediatly adjacent to the dead ones. I detected no caterpillar damage. Any ideas what happened?


Texas Mountain Laurel, Sophora secundiflora is famously resistant to most pests and diseases; the one major exception being the Genista caterpillar which attacks the leaves. However, the phenomena you described are pretty classic symptoms of a wilt disease. Wilts are usually caused by fungal pathogens invading and clogging vascular tissue in roots or stems of plants, thus the sudden decline of the plant. Species of fungi within the genera Verticillium and Fusarium would be the most likely cause of the disease, but Texas Mountain Laurel is not known to be particularly susceptible to any of them.

There are other possibilities, but without actually examining the plants, it would be difficult to rule any cause either in or out. You should contact your county agricultural extension agent for information on having samples from your dead plants tested to determine the cause of the problem.

More Trees Questions

Spraying paint on White Pine tree trunks
October 31, 2011 - Is there a paint that is safe to spray on a tree trunk without damaging/killing the tree? We have White Pines that have ~16" spacing without limbs & would like to 'camouflage' the bare space. If pa...
view the full question and answer

Pecan tree dropping dead leaves
August 02, 2014 - I have a very old, tall pecan tree in my yard that has been dropping dead leaves for the last three weeks. My back yard looks like it is the Fall season. Do you have any insight on this?
view the full question and answer

Evergreens for a deer corridor in MI
April 16, 2012 - I am growing three rows of evergreens for a wildlife, deer travel corridor, and am looking for which trees grow well together and are shade tolerant of each other when planted at the same time, or at ...
view the full question and answer

Allelopathy in Sassafras albidum
January 11, 2012 - Sassafras albidum description says "Sassafras is allelopathic and can discourage the growth of certain other plants within its root zone." My question is: WHICH plants are susce...
view the full question and answer

How close to a female tree will a male Possumhaw Holly need to be planted to ensure pollination in Plano, TX?
April 01, 2010 - I would like to plant a female Possumhaw Holly in my yard. Does a male need to be planted nearby in order for the female to have berries? If so, how close must the male tree be located?
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.
© 2015 Lady Bird Johnson Wildflower Center