Help with Gardenias

Hi guys,
I recently moved into a new house in Arizona and found 3 half dead Gardenia bushes on the side yard. The first thing I did was make sure the drips were on (which they barely were). Then I pruned all the yellow/dead leaves and empty branches off. I also watered them with coffee grounds and epsom salt around the bases. Can you guys give me some tips on what else I could do to help them along?

I attached some pictures to help.

Attachment 450 Attachment 451 Attachment 452
thanks,
Steve