"They are both on timed drip irrigation."

You've given us very very little to go on here, but the drip irrigation comment may be a key to the problem. Why do you have them on drip irrigation? Are they new transplants or something? Do you manually check the soil moisture on a regular basis? Is the soil drying out sufficiently in between waterings?

My Deodar Cedar just started having a lot of dead branch tips, the tender new growth. I just noticed it today all over one tree, and some on another tree about 100' from the first. They are both on timed drip irrigation.

I have some shrubs with hail damage in the yard.

Dan

We're in Southern California, and it will not rain between May and November. The trees are about 25 feet tall; since we do not have a lawn, the drip is all the water they get. It gives them about 4 gallons of water four times a week.

Might be worth checking soil salinity levels.

Resin