[Arid_gardener] texas ebony help!

[Cathy.Rymer at chandleraz.gov]

Hi Mary,

Thanks for your question.  Texas Ebony trees are native to south Texas and 
Mexico and are known for their dark green leaves and twisted gray 
branches.  White, puffball flowers are followed by large, woody, dark 
brown pods. 

Your tree could have been neglected prior to your purchase of the home. 
Mature trees require very little water as long as moisture soaks down to 
at least three feet in the ground when it is applied.  Watering the entire 
root zone deeply once every three weeks in the summer tapering to once 
every 4-6 weeks in winter should be adequate.  You can apply water as Dick 
recommended or just lay the hose and let the water trickle overnight at 
the drip line at several places. 

Your tree could have been over pruned.  This tree does not seem to 
tolerate pruning well here in our location in the low desert.  Pruning any 
tree is stressful and most trees can tolerate minor pruning without any 
problem.  Removing too much foliage (more than 25 percent in any year) can 
send trees into a stress mode.  In the process they give off chemical 
signals that can attract pests.  In the case of Texas Ebony, pruning seems 
to attract one of the flathead borers.  This metallic bronze-colored 
beetle lays its eggs on the branches of the tree.  The eggs hatch and 
larvae burrow into the tree just under the bark where they spend the next 
year or so tunneling and eating the branch tissues. 

If you noticed elliptical holes approximately 1/4 inch in diameter on the 
dying/dead branches, you are dealing with the flatheaded borer.  The holes 
are where the mature beetle has emerged from the branch.  You may also 
notice sawdust-like wood in the dead branches as well which is left behind 
as the beetle larvae munches the branch.  Occasionally, you may see one of 
the cream-colored larvae just under the bark of an affected branch.  They 
have an enlarged head which is flattened with a legless, segmented body.

Because the larvae are hidden within the wood of the tree, chemical 
treatments are ineffective.  The best course of action is to make sure 
your tree is as healthy as possible and limit pruning.  Here is a link to 
the Master Gardener Manual which has illustrations and descriptions of 
this insect pest. 
http://cals.arizona.edu/pubs/garden/mg/entomology/sap.html#trunk

Please let me know if you have any questions.  I'm happy to help.

Cathy Rymer
Certified Arborist
Master Gardener U of A Cooperative Extension


>>>>>>>>>>
Hi All,

I am new to this forum. I live in Phoenix, AZ.

I am concerned about a Texas Ebony in our front yard. The tree has western 
exposure. This tree is about 12 years old (we just bought the house 2 
years ago). In the last 3 months or so we started noticing that the 
branches on the tree are slowly dying. About 2 months ago, we removed the 
dead branches. However, another large branch has now suddenly died. There 
is no irrigation to this tree...but we gave it water and that did not seem 
to help. There are several areas of new growth at the base of the tree. 
Any idea what is killing this tree? 
Thanks in advance!! Mary
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