Question
We live in the high desert of souther California, where temperatures can range from 115 to 120 degrees.  We have an oleander tree that is about 12 years olds.  One side of the tree has started to die and we noticed on the dying side the bark is all checked,cracked, and easily comes off. This side also receives the direct sun light.  What might be the cause of this and is there anything we can do to save the tree?

Answer
Hi Tom,
Thanx for your question. I'm very familiar with oleander.  It is a very popular shrub for public plantings throughout Southern Arizona, California, Texas and Florida not to mention other places.

Please check this link out.
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7480.html  This concerns a new type of pest that has become a problem with Southern California oleanders.

The other type of leaf scorch can be treated by mulching around the plant.  Remove the dead material and water once a week if no regular rain so that the plants gets an equivalent of one inch of water.  A good weekly soaking with the garden hose can take care of this.  I hope this helps.

You may want to contact your county extension office.  If you'll give me your county, I'll get you contact information.  

Tom