Hedge shedding leaves

My grisilena hedge ( about 20 years old ) has shed a large amount of its leaves in past month and is now rather bare and very thin looking. I have also seen this in other hedges. I am worried that it may be in serious trouble. I have heard that it should be sprayed with "liquid copper" and fertiliser added to its base. Any assistance to what i could do?

hi have these planted only about three years and alot of leaves turned brownish and top leaders drooping. Asked in local garden centre and was told to "leave everything alone that looks like dying or dead as nature is a wonderful thing and only thing that you need to do at moment is remove leaves from the cordyline plants". My grass is another thing, hope it recovers.......

re- Hedge shedding leaves
I too have a grisilena hedge which has shed a lot of leaves
I first noticed it around October last year it was cut back around September I think it has black spot and there is a power like substance around the root dont know what to do with it as its looking very bad

I often read Gerry Daly on . If you do a search on the site you might find some helpful information - he often answers queries about lawns, etc.