Host an Event Volunteer Join Tickets

Support the plant database you love!

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

Sunday - August 01, 2010

From: Las Vegas, NV
Region: Rocky Mountain
Topic: Diseases and Disorders, Watering
Title: Arizona ash tree with brown leaf tips in Las Vegas NV
Answered by: Barbara Medford

QUESTION:

We've had an Arizona Ash Tree in our yard for over 7 years it was doing fine until last summer, the tree seems to be struggling with the heat, its leaves look like they are burning up and turning brown at the very top, is there anything we can do to help it?

ANSWER:

According to this USDA Plant Profile Map, Fraxinus velutina (velvet ash) grows natively in your area of Clark County, USDA Plant Hardiness Zones 8b to 9b, so your problem should not be with soil or climate. Unless you are having a most unusually hot summer, hotter than last year, 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 are wondering if perhaps you are having an unusually dry year in Nevada and that underground water has diminished. 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 and nutrition 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, contact the University of Nevada Cooperative Extension Office for Clark County. 

 

More Watering Questions

Repotting of lemon cypress for drainage
October 26, 2008 - Hi, I bought a lemon cypress tree in a nice tin, It is in Plastic and the bottom has about 1.5" of water with no drainage in the plastic or tin. It will be kept inside. Does the plant need to be in...
view the full question and answer

Failure to bloom of Texas Mountain Laurel
April 15, 2008 - My +/- 4 yr old Tx. Mountain Laurel, has never bloomed. It is in full sun. I sometimes (minimal) fertilize it. I've pretty much planted it and let it grow. Its been pruned back last year when som...
view the full question and answer

How to care for newly transplanted Live Oak.
July 02, 2009 - I planted 3 B & B, 6" caliper live oaks in February and they lost most of their leaves during the normal time but when the new leaves grew back the amount of leaves were quite a bit less. I have th...
view the full question and answer

Brown, dry leaves on weeping willow tree
May 01, 2008 - We live in central TX and have just planted a weeping willow tree. Our back yard has a retention pond and ravine that parallels our property and we were told that the weeping willow will do perfectly ...
view the full question and answer

Recovery of water-stressed Agarita
August 11, 2014 - Hello! I planted a small agarita at the end of May and then left town for six weeks. During that time it was supposed to receive weekly deep irrigations to help it establish, but it seems that som...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.