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

Friday - August 12, 2011

From: Corinth, TX
Region: Southwest
Topic: Diseases and Disorders, Watering, Trees
Title: Cedar elm with brown leaves
Answered by: Nan Hampton


Dear Mr. Smarty Plants, We feel we may have limited time to save our beautiful Ceder Elm. We have many trees in our yard (Post Oaks and Cedar Elms) and have been told they are all between 50 - 75 years old.About two months ago we noticed one of the Cedar Elms started to get rust colored edges on all the leaves. I thought it was because we had not had much rain and tried deep watering. This month however several entire branches have turned brown. I think the tree may have Bacterial Leaf Scorch. Any advice you may be able to offer would be so greatly appreciated. Also thank you for reading my email. Grace Ward


It is possible that your Ulmus crassifolia (Cedar elm) has bacterial leaf scorch.  TAMU AgriLIFE Extension Texas Plant Disease Handbook's entry for Elm (Ulmus spp.) lists common diseases and pests and elm bacterial leaf scorch is listed as one of them.  This article from the United States National Arboretum certainly describes symptoms similar to those of your trees, however, the article says:

"The challenge is that the symptoms can be easily mistaken for physiological leaf scorch or early fall color. However, since a number of other diseases, as well as cultural problems, can mimic bacterial leaf scorch symptoms, it has been recommended that suspected infections be confirmed by sending samples to a diagnostic clinic before concluding the tree is infected with the bacterium."

If your tree does have bacterial leaf scorch, I'm afraid there isn't any effective treatment for it—either for curing it or preventing it.  The best thing you can do is to prune and keep the tree looking as nice as possible for as long as possible until it dies.  You can check with your Denton County Texas AgriLIFE Extension Service office to see if bacterial leaf scorch has been reported in the area.  A professional arborist should be able to tell you if your tree is infected with bacterial leaf scorch.   You can go to TreesAreGood.com and plug in your zipcode to find a professional arborist for your area.

Even though bacterial leaf scorch is a possibility, given the severity and length of our current drought, your tree may just be experiencing drought stress even though it is described as a drought tolerant tree. You said that you had done some watering.  Are you still watering?   If you aren't watering, you should be.  You can find an article from the City of Austin Urban Forestry Division, Supplemental Watering of Trees During Periods of Drought, with detailed recommendations on how much and how to water as well as other measures that will help drought-stressed trees.  I do know that cedar elms are one of the first deciduous trees to turn yellow and lose their leaves in the fall.  Your tree may just be reacting to the stress by doing this earlier than usual and may leafout normally in the spring.  Watering will help it recover if that is the case.


From the Image Gallery

Cedar elm
Ulmus crassifolia

Cedar elm
Ulmus crassifolia

Cedar elm
Ulmus crassifolia

More Trees Questions

Identity of a plant that may be a horse apple (Maclura) in Springtown, TX.
July 21, 2009 - I have a tree that I think is a crab apple, however, I can't find it in any collection on internet. The fruit looks like light green colored apples, however, they are very hard and very course textu...
view the full question and answer

Fragrant perennial plants for shade in Dallas
July 11, 2011 - I am looking for shade-loving perennial plants to provide fragrance in my garden. What plants would you recommend for my North Texas (Dallas) garden that is fully shaded by huge pecan trees? My curren...
view the full question and answer

Adjustments to soil level change around tree from Austin
May 29, 2014 - I am moving in to a new construction home in south Austin, builder has leveled the ground and sodded the front yard, I have a post oak in the front and because of the changes to the landscape the tree...
view the full question and answer

Looking for copper beach (Fagus sylvatica)
December 05, 2008 - I would like to purchase a copper beech tree to plant in CT as a gift. Where can I find one to purchase?
view the full question and answer

Conditions for growing Prunus mexicana
March 23, 2007 - Will a native Wild Plum do well in the Cat Spring area west of Houston. The soil is quite sandy. I was told that the plum trees attract deer.
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2015 Lady Bird Johnson Wildflower Center