Q.Holly bushes
The leaves on my holly bush are disappearing. In some areas, all that remains are stems which eventually die. Out of 50 plants, 6 have been defective. Two of the plants are together but the others seem random. The leaves do not appear to be eaten or fallen to the ground.
There could be many reasons for the die back of Holly.
Inspect the plants carefully for more clues as to the issue.
Look for insects and or damage to leaves.
Remove any dead or diseased material and clean up the fallen leaves--dispose of this material.
Here is a link that lists the most common insects and disease.