Your Oleanders have scale. I have an Oleander jungle but was able to save them last summer with a systemic treatment. You can get advise on what you need at your local nursery. You must spray them when the sun is not on them and wear protective clothing and gloves when applying. Hope this helps out Zach

Hi - I found an effective way to deal with Oleander Gall / Leaf Scorch. 1. Fill a spray bottle with a mixture of 25% - 50% rubbing alcohol and water. 2. Cut off ALL branches with ANY evidence of galls or leaf scorch. 3. Spray the cut ends with the alcohol/water mix. Worked great for me here in Northern California.

Sometimes leaf scorch is not scorch but the plants need water. It has been a very dry year this year.
Mickey
Arizona