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
Not Yet Rated

Saturday - August 07, 2010

From: New Braunfels, TX
Region: Southwest
Topic: Trees
Title: Leaf problems on Arizona ash in New Braunfels, TX
Answered by: Barbara Medford

QUESTION:

I have an Arizona Ash tree that is 10 years old. The leaves have brown spots all over and then eventually the leaves curl up and fall off the tree. Is this a fungus or a bacterial infestation? What should I use to clear this up?

ANSWER:

According to this USDA Plant Profile Map, Fraxinus velutina (velvet ash) does not grow natively in your area of Comal and Guadalupe Counties, USDA Plant Hardiness Zone 8a, so your problem could be with soil or climate. However, if the tree has grown there for 10 years, it's hard to understand why it would just now be showing these symptoms.  Up until August 1, we have had a relatively mild and damp summer, so heat stress doesn't seem to be indicated. Therefore, you need to ask yourself what in the environment has changed to cause that tree to have leaf tips browning?

We will do a little research into the Arizona Ash and see if we can find what might be causing a symptom you have not seen before. None of the sites we looked at mentioned any disease that caused that sort of leaf browning, but there were several mentions that this tree depended on an underground water source or was "riparian" meaning it likes river bottoms or other locales where there is a constant supply of water for its roots. We have had some rain in Central Texas, but perhaps for other reasons underground water has diminished, especially now that the "wet spell" is over and the heat is digging in. One source recommended deep irrigations of the tree two or three times a month during extremely dry spells. This would mean getting a hose down in the dirt around the roots, turning it on to a slow dribble and letting it run until water appears on the soil surface. The leaves browning at the top of the tree would seem to be indicative of this, as all the moisture for the tree comes up from the roots. The leaves at the very top, the end of the line, as it were, would be most susceptible to moisture deprivation. 

Another possibility, although more remote, is that of ash borers. See this article from Colorado State University Extension on Ash Borers.  This article points out that borers are more apt to attack trees weakened from drought or other reasons. However, first see if there are any signs of the beetles before you try pesticide. For more information on the possibility of ash borers in your vicinity, or other diseases that have appeared in the area, contact the Texas Cooperative Extension Offices for Comal County or Guadalupe County

Pictures of Fraxinus velutina (velvet ash) from Google.

 
 

More Trees Questions

Blackening of top growth of yaupon in Sunrise Beach TX
June 09, 2010 - My question regards a Will Flemming yaupon which I am thinking may be within your scope of expertise. These were recently planted under windy conditions, then hit with a neighbors antiquated jet type ...
view the full question and answer

Stressed Texas persimmon, Diospyros texana
September 12, 2009 - I planted a 5' Texas Persimmon last May..it is watered by drip irrigation and has done well, putting on lots of new leaves and looking healthy as can be. That is, until several days ago when it began...
view the full question and answer

Fruit trees for South Austin.
January 25, 2008 - I live in South, South Austin, just a pinch West of 35 near 1626. I would like to plant some fruit trees in the back yard. Anyone will sell fruit trees, but they don't always grow. What fruiting var...
view the full question and answer

Live Oak Mess in Liberty, TX
April 09, 2015 - Should I leave the pollination debris that has fallen from my 3 historic live oaks on the ground surface beneath them or use a leaf blower to remove.
view the full question and answer

Tree with tap root for small area near Dallas
September 07, 2009 - Mr. Smarty Plants, I live in Coppell, TX (a suburb of Dallas) & am looking for a tree to plant near our pool to provide some shade. The current tree (a silver leaf maple) is dying. My husband thi...
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 | SITEMAP | STAFF
© 2016 Lady Bird Johnson Wildflower Center