Native Plants
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.
Did you know you can access the Native Plant Information Network with your web-enabled smartphone?
Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.
rate this answer
Wednesday - July 13, 2016
From: Boerne, TX
Region: Southwest
Topic: Diseases and Disorders, Trees
Title: Young Mexican White Oak Losing Leaves in Texas
Answered by: Anne Van Nest
QUESTION:
I have a 5 yr old Mexican white oak, 20 ft tall losing its leaves mostly at the top. They turn brown & fall off. It does not lose its leaves in the winter, right?. About 3 ft from the top down is bare, The root flanges are not showing at the base. Could the dirt be piled too high around the trunk? I am letting my hose slowly drip in case it is just too dry. What do you think? Do I have a problem?ANSWER:
Mexican White Oak (Quercus polymorpha), according to the Texas A&M Forest Service says that this tree is only recently discovered in the U.S. (1992) as a native tree species, but widely available in commercial nurseries. Naturally occurring only in one known U.S. population, near the Devil's River in Val Verde county, but more common in Mexico. Now planted widely as a landscape tree.
The leaves are simple, alternate, 2" to 5" long, highly variable, but often with several shallow lobes or teeth towards the tip. Leaves are thick, leathery, and semi-evergreen, with distinct raised veins on the yellowish underside. New leaves in spring are peach-colored and in colder climates the leaves are late-deciduous and turn yellow-brown.
The Native Plant Database lists this tree as Monterrey Oak as well as Mexican white oak and Netleaf white oak.
Your comment about the root flare is a potential problem. Soil and mulch should not be mounded up around the trunk higher than the root flare. Howard Garrett, The Dirt Doctor has information and images on his website about Root Flare Management that may be of help to you in determining if your tree is planted too deeply.
From the Image Gallery
More Trees Questions
Are there male and female mesquite trees and do both have seeds?
September 22, 2010 - Do both male and female mesquite trees (all species) have seed pods?
view the full question and answer
Leaves wrinkling on Tecoma stans from San Antonio TX
August 16, 2013 - My two year old esperanza (planted in the ground) froze back last winter, came back from the roots & has been doing well all summer. Recently one branch has leaves that are nice & green but very wrin...
view the full question and answer
Low maintenance replacement garden in Ashburn , VA
April 30, 2009 - We live in Ashburn, VA (Northern VA). Our house is 10 years old and the contractor grade plants have died. We are planning on digging everything up and re-doing the landscaping in our front yard - r...
view the full question and answer
How to treat bark damage on oak tree
November 15, 2011 - I have an oak tree approx. 50 ft., live in austin, texas. the tree has dropped bark about 3-4 ft above ground, in a section of 4 inches by 8 inches, and the tree appears dark where the bark was. is ...
view the full question and answer
Junipers for restoring area in Bulverde TX
November 03, 2012 - Are ashe or virginiana junipers for sale around the hill country? I would like to recreate the natural plant life that was bulldozed next to my home. Do you recommend any other types of juniper that ...
view the full question and answer
Support the Wildflower Center by Donating Online or Becoming a Member today. |