Griselinia hedge dead help!

[Hedge guy]

Hi, first post here as I am totally perplexed and in need of advice,
 

We have an established Griselinia hedge. Neighbour snapped by hand the branches off so that he could see over the hedge. Leaves then turned yellow and all have now dropped off after 2 months, the hedge is now bare and branches are black. In addition we also have an alder tree and poplar tree. Person snapped the top part of the trees both are now dead.

 

After the damage occurred it was dry for a long time and wind was cold. Could it be that the plants were stressed, or do you suspect that it is something else. 

 

Thank you so much for your help

[dumper]

1 hour ago, tomo567 said:

I thought griselinia was good in costal areas that was exposed to a lot of salt in the air

Yep salt in the air not concentrated solution 

[openspaceman]

53 minutes ago, dumper said:

Yep salt in the air not concentrated solution 

Yes salt tolerant species may survive with some salt but high concentrations will kill.

 

We see a salt tolerant plant with a small white flower growing adjacent to roads that have been salted in the winter but as summer rains wash the salt out other plants become established