My Holly Bush Has Some Leaves Turning Yellow & Falling Off, The Branches Are Pretty Sparce, Can You Advise Of Any Cause & Treatmen

Answer 1

This is usually caused by a lack of iron, and can be in combination with other factors including pH swings, overwatering, among many others.

Here is an article that will help:

https://www.gardeningknowhow.com/ornamental/shrubs/holly/holly-yellow-leaves.htm