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
1 rating

Thursday - April 05, 2012

From: Phoenix, AZ
Region: Southwest
Topic: Diseases and Disorders, Trees
Title: Texas wild olive tree
Answered by: Ray Mathews


I live in the Phoenix area. My Texas wild olive (Cordia boissieri) is about 5 years old, about 12 feet tall and has beautiful blossoms all year long. However, this past year (through all seasons) some of its leaves developed yellow/brown spots and other leaves are completely brown and falling off. I am not able to find much information on the diseases of this plant. Might this be a lack of N2? a mold? overwatering? ???? Any guidance you might be able to provide would be appreciated. Thank you.


The wild olive tree Cordia boissieri (Mexican olive) is an evergreen native only to Texas in the U.S.,  but also to several states in northern and southern Mexico, including Coahuila, Nuevo Leon, San Luis Potosi, Tamaulipas, and Veracruz, per the following Agricultural Research Service, Germplasm Resources Information Network link. This rare small tree is reportedly ideal as an ornamental for confined areas. It is drought tolerant and insect and disease pests are generally of no concern. Birds and other wildlife feed on the fruit. It blooms in late May through early June.

However, since Cordia boissieri isn’t native in Arizona , it may be the wrong plant for Arizona. The symptoms you are observing may be due to mold or overwatering. We don't believe that nitrogen deficiency is the problem.

Bill Britt’s garden website offers the possibility of frost as an immediate cause, but the earlier browning does not follow the description for these symptoms?

We believe that you need someone who can look at the plant, and make an informed assessment. For that we suggest you contact the folks at the Maricopa County Office of Arizona Cooperative Extension for some help closer to home.





From the Image Gallery

Mexican olive
Cordia boissieri

More Diseases and Disorders Questions

Growths on Shumard Red Oak leaves from Katy TX
April 01, 2013 - Our beautiful Shumard Red Oak has developed lots of light green grape like growths on the leaves. Please inform us what this could be and how we should treat it?
view the full question and answer

Dying trees in San Marcos, Texas
September 24, 2011 - I live on 11 acres in San Marcos and cannot water at all during this drought. All of my oaks and mountain laurels are turning brown. Does this mean they are all dying? Will they come back in the sp...
view the full question and answer

Disease or insect damage on a Mexican plum
September 08, 2013 - Help, Our Mexican plum tree is about 13-14 years old. Earlier this year we noticed the trunk is oozing black stuff and whole branches are dying off. We have watched as our beloved tree has lost most ...
view the full question and answer

Live oak leaves yellowing from Denton TX
January 26, 2012 - In autumn of 2010 I planted 10 live oaks about 6 to 7 ft. tall. I have see that during the month of Dec. 2011 to Jan. 2012 they are showing some yellow leaves. What can I do to help them?
view the full question and answer

Problems with non-native photinia in Austin
October 07, 2013 - Hi, I live in Cedar Park, TX (Austin Suburb)and have planted a number of Photinia shrubs in various areas of my property. All about 10 months old. The leaves are curling along their length on many...
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