Ligustrum lost too many leaves

[CrsytalB]

I moved into a property 7 years ago which had a Ligustrum Tree (approx 20 years old & about 18 ft tall )

 

I have it trimmed/pruned every year and so far it has always looked healthy....until this year.

 

It has lost a lot of it leaves leaving it looking sparse and straggly.

 

Although it has never been a very dense tree and only has 12 inches of leaves at the end of the branches, it has always looked full.

 

We did have a storm last year, and the tree did take a bashing, swaying back and forth, maybe this caused the problem?

 

I thought it may look better after a trim last month, but it looks worse, sparser.

 

The leaves are all looking healthy except a few brown ones here and there which I think is normal shedding. he trunk also looks normal.

 

The tree surgeon that cuts it every year has spoken to some tree surgeon colleagues who have suggested digging around the roots and adding some feed. I will try this, but any other advice or suggestions would be greatly appreciated.

 

Many Thanks